Faculty Profiles

Emu, I. H., Samuels, B. C., Karmakar, S., Hamid, M. A., Shiam, I. F., Sarkar, P. K., … Droopad, R. (2025). Epitaxial growth and characterization of copper gallate (CuGa2O4) thin films by pulsed laser deposition. Materials Science in Semiconductor Processing, 185, 108934 1-11. https://doi.org/https://doi.org/10.1016/j.mssp.2024.108934

Karmakar, S., Emu, I. H., Halim, M. A., Sarkar, P. K., Sultana, M., Tasnim, A., … Haque, A. (2024). Growth Optimization, Optical, and Dielectric Properties of Heteroepitaxially Grown Ultrawide-Bandgap ZnGa2O4 (111) Thin Film. Journal of Applied Physics, 135, 115702-1–11. https://doi.org/https://doi.org/10.1063/5.0190906

Karmakar, S., Shiam, I. F., Droopad, R., & Haque, A. (2024). Enriched electron donor sites and non-overlapping small polaron tunneling electrical conduction in oxygen-deficient β-Ga2O3 thin film on p-Si (100). Applied Physics A, 130. https://doi.org/https://link.springer.com/article/10.1007/s00339-024-07656-8

Haque, S., Shiam, I. F., Manikanthababu, N., Droopad, R., & Haque, A. (2024). Upheaval of Negative Dielectric Permittivity and Semiconductor to Metallic Transition in a Thermally Induced Sn-Doped β-Ga2O3 (−201) Single Crystal. ACS Applied Materials & Interfaces, 48488–48501. https://doi.org/doi.org/10.1021/acsami.4c08604

Hamid, M. A., Samuels, B. C., Emu, I. H., Sarkar, P. K. C., Tasnim, A., Saha, R. C., … Droopad, R. (2024). Impact of Thermal Annealing on Properties of MgGa2O4 Thin Films in Oxygen Ambience. ACS Applied Electronic Materials, 6(12). Retrieved from https://pubs.acs.org/doi/abs/10.1021/acsaelm.4c01481

Droopad, R., Petraru, A., Gronenberg, O., Shurmann, U., Kienke, L., & Kohlstedt, H. (2024). Distinguishing the Rhombohedral Phase from Orthorhombic Phases in Epitaxial Doped HfO2 Ferroelectric Films. ACS Applied Materials and Interfaces, 16(36), 42534–42545. https://doi.org/https://doi.org/10.1021/acsami.4c10423

Karmakar, S., Parey, V., Mistari, C., Emu, I. H., Halim, M. A., Sanyal, G., … Haque, A. (2024). Electric field emission in GdNiO3 microflower. Materials Today Communications, 40. https://doi.org/https://doi.org/10.1016/j.mtcomm.2024.109632

Droopad, R., Radhakrishnan, G., Kim, K., & Goyal, A. (2024). Heteroepitaxial GaAs thin‑films on flexible, large‑area, single‑crystal‑like substrates for wide‑ranging optoelectronic applications. Scientific Reports, 14. https://doi.org/https://doi.org/10.1038/s41598-024-59686-0

Droopad, R., Samuels, B. C., Taqy, S. A. A., Weston, K., & Taylor, R. (2024). Aerosol assisted-chemical vapour deposition of tetrahedrite copper antimony sulphide thin films: the effect of zinc(II) impurities on optical properties. Thin Solid Films, 797, 140345. https://doi.org/https://doi.org/10.1016/j.tsf.2024.140345

Taqy, S., Sarkar, P., Hamid, M. A., Pranto, T., Piner, E. L., Droopad, R., & Haque, A. (2024). Diamond Deposition on AlN Using Q-Carbon Interlayer Through Overcoming the Substrate Limitations. Carbon, 219, 118809 1-13. https://doi.org/10.1016/j.carbon.2024.118809

Hamid, M. A., Samuels, B. C., Karmakar, S., Halim, M. A., Emu, I. H., Sarkar, P. K., … Droopad, R. (2023). Epitaxial Growth and Characterization of Magnesium Gallate (MgGa2O4) Thin Films by Pulsed Laser Deposition. Journal of Alloys and Compounds, 972, 172807.

Karmakar, S., Sarkar, P. K., Mistari, C. D., Trivedi, R. K., Chakraborty, B., More, M., … Haque, A. (2023). Tubular Diamond as an Efficient Electron Field Emitter. ACS Applied Electronic Materials, 5(7), 3592−3602. https://doi.org/https://doi.org/10.1021/acsaelm.3c00317

Karmakar, S., Droopad, R., Mathew, A., Mohanty, H. S., Rahaman, I., Behera, D., & Haque, A. (2023). Temperature-driven complex dielectric and polaron-hopping mediated electrical conduction in aurivillius Gd2MoO6. Journal of Alloys and Compounds, 955, 170271. https://doi.org/https://doi.org/10.1016/j.jallcom.2023.170271

Droopad, R., Fox, Z. I., Das, S. S., Samuels, B. C., Mia, M. D., & Saha, R. (2023). Demonstration of ferroelectricity in PLD grown HfO2-ZrO2 nanolaminates. AIMS Materials Science, 10(2), 342–355. https://doi.org/10.3934/matersci.2023018

Haque, A., Karmakar, S., Trivedi, R. K., Chakraborty, B., & Droopad, R. (2023). Electric-Field Emission Mechanism in Q-Carbon Field Emitters. ACS Omega, 8(10), 9307–9318. https://doi.org/https://doi.org/10.1021/acsomega.2c07576

Karmakar, S., Taqy, S., Droopad, R., Trivedi, R., Chakraborty, B., & Haque, A. (2023). Highly Stable Electrochemical Supercapacitor Performance of Self-Assembled Ferromagnetic Q-carbon. ACS Applied Materials & Interfaces. https://doi.org/https://doi.org/10.1021/acsami.2c20202

Dey, T., Reza, M. S., Arbogast, A. W., Holtz, M. W., Droopad, R., Bank,Seth R., & Wistey, M. A. (2022). Molecular beam epitaxy of highly crystalline GeSnC using CBr4 at low temperatures. Applied Physics Letters, 121(12), 122104. https://doi.org/10.1063/5.0102093

Kim, K., Radhakrishnan, G., Droopad, R., & Goyal, A. (2022). Single-crystal-like germanium thin films on large-area, compliant, light-weight, flexible, single-crystal-like substrates. PNAS Nexus, 1, 1–7.

Mia, M. D., Samuels, B. C., Anderson, J., Haque, A., & Droopad, R. (2022). Growth and characterization of (Ga1− xFex) 2O3 thin films by pulsed laser deposition for wide-bandgap and spintronics applications. MRS Communications, 12, 422–426. https://doi.org/10.1557/s43579-022-00194-5

Mia, D., Samuels, B., Borges, P., Scolfaro, L., Siddique, A., Saha, J., … Droopad, R. (2022). Growth and characterization of ( Ga1 − xGdx)2O3 by pulsed laser deposition for wide bandgap applications. Applied Physics A: Material Science and Processing, 128, 366. https://doi.org/10.1007/s00339-022-05476-2

Scolfaro, L. M., Mia, M. D., Talukder, M. A. A., Samuels, B. C., Borges, P., Geerts, W. J., & Droopad, R. (n.d.). Stability and Electronic Properties of Ga2O3 :Fe Alloys Studied Using Density Functional Theory Calculations.

Droopad, R., Scolfaro, L. M., Geerts, W. J., Mia, M. D., Samuels, B. C., & Talukder, M. A. A. (2021). Theoretical and experimental study of  (Ga1-XFeX)2O3 ternary alloy. Journal of Crystal Growth, 575. https://doi.org/https://doi.org/10.1016/j.jcrysgro.2021.126353

Mia, M. D., Samuels, B. C., Talukder, M. A. A., & Droopad, R. (2020). Wide Bandgap Ga2O3 based alloys by Pulsed laser Deposition.

Pandey, R. K., Droopad, R., & Stern, H. P. (2019). Magnetic field sensor based on varistor response. IEEE Sensors Journal, 19, 8635.

Petraru, A., Droopad, R., & Kohlstedt, H. (2019). Characterization of VO2/ferroelectric thin film heterostructures deposited on various complex oxide single crystal substrates. Journal of Vacuun Science and Technology A, 37, 21514.

Farshchian, B., Gatabi, J. R., Bernick, S. M., Lee, G.-H., Droopad, R., & Kim, N. (2018). Scaling and mechanism of droplet arrays formation on a laser-patterned PDMS with a superhydrophobic grid. Colloids and Surfaces A, 547, 49–55.

Tang, K., Droopad, R., & McIntyre, P. (2018). Bias temperature stress induced hydrogen depassivation from Al2O3/InGaAs interface defects. Journal of Applied Physics, 123(2), 25708.

Arias, A., Nedev, N., Ghose, S., Rojas-Ramirez, J., & Droopad, R. (2018). Structural, Optical, and Electrical Characterization of beta-Ga2O3 Thin Films Grown by Plasma-Assisted Molecular Beam Epitaxy Suitable for UV Sensing. ADVANCES IN MATERIALS SCIENCE AND ENGINEERING.

Droopad, R., Ghose, S., Rahman, S., Rojas-Ramirez, J., Jin, H., Park, K., … Hong, L. (2017). Growth and characterization of Ga2O3 thin films by molecular beam epitaxy for deep-UV photodetectors. Journal of Applied Physics, 122, 095302.

Droopad, R., Hong, L., Bhatnagar, K., Klie, R., & Ogut, S. (2017). Atomic-scale structural and electronic properties of SrTiO3/GaAs interfaces: A combined STEM-EELS and first-principles study. Physical Review B, 96, 035311.

Droopad, R., Gatabi, J., Rahman, S., Amaro, A., Nash, T., Rojas-Ramirez, J., & Pandey, R. (2017). Tuning electrical properties of PZT film deposited by Pulsed Laser Deposition. Ceramics International, 43, 6008.

Droopad, R., Edmonds, M., Wolf, S., Chagarov, E., Kent, T., Park, J., … Kummel, A. (2017). Self-limiting CVD of a passivating SiOx control layer on InGaAs(001)-(2x4) with the prevention of III-V oxidation. Surface Science, 660, 31.

Droopad, R., Tang, K., Palumbo, F., Zhang, L., & McIntyre, P. (2017). Interface Defect Hydrogen Depassivation and Capacitance-Voltage Hysteresis of Al2O3/InGaAs Gate Stacks. ACS Applied Materials and Interfaces, 9, 7819.

Droopad, R., Qin, X., Wang, W.-E., Rodder, M., & Wallace, R. (2017). A crystalline oxide passivation on In0.53Ga0.47As (100). Journal of Applied Physics, 121, 125302.

Droopad, R., Cortes-Mestizo, I., Briones, E., Yee-rendon, C., Zamora Peredo, L., Espinosa-Vega, L., & Mendez-garcia, V. (2017). Optical spectroscopy analysis of the near surface depletion layer in AlGaAs/GaAs heterostructures grown by MBE. Journal of Crystal Growth, 477, 59–64.

Farshchian, B., Gatabi, J., Bernick, S., Park, S., Lee, G.-H., Droopad, R., & Kim, N. (2017). Laser-induced superhydrophobic grid patterns on PDMS for droplet arrays formation. Applied Surface Science, 396, 359.

Droopad, R., Fu, Y.-C., Peralagu, U., Miller, D., Lin, J., Povey, I., … Thayne, I. (2017). The impact of forming gas annealing on the electrical characteristics of sulfur passivated Al2O3/In0.53Ga0.47As (110) metal-oxide-semiconductor capacitors. Applied Physics Letters, 110, 142905.

Droopad, R., Briones, E., Cortes-Mestizo, I., Briones, J., Espinosa-Vega, L., Vilchis, H., & Mendez-Garcia, V. (2017). Efficiency of broadband terahertz rectennas based on self-switching nanodiodes. Journal of Photonics for Energy, 7, 25001.

Cortes-Mestizo, I. E., Briones, E., Briones, J., Droopad, R., Perez-Caro, M., McMurtry, S., … Mendez-Garcia, V. H. (2016). Study of InAlAs/InGaAs self-switching diodes for energy harvesting applications. Japanese Journal of Applied Physics, 55(014304).

Droopad, R. (2016). A Nonlinear Circuit Simulation of Switching Process in Resonant Tunneling Diodes. IEEE Transactions on Electron Devices, 63, 4993.

Droopad, R., Rahman, M. S., & Ghose, S. (2016). Integration of BiFeO3/La0.7Sr0.3MnO3 heterostructures with III-V semiconductors for low-power non-volatile memory and multiferroic field effect transistors. Journal of Material Chemistry, 4, 10386.

Droopad, R. (2016). Temperature Dependent Border Trap Response Produced by a Defective Interfacial Oxide Layer in Al2O3/InGaAs Gate Stacks. ACS Applied Material and Interface, 8, 30601.

Droopad, R. (2016). Performance evaluation of broken gap Esaki tunnel diodes on Si and GaSb substrates,. Electronic Letters, 52, 73.

Droopad, R. (2016). InAs FinFETs With H-fin=20 nm Fabricated Using a Top-Down Etch Process. IEEE Electronic Device Letters, 37, 261.

Droopad, R. (2016). Determination of the depletion layer width and effects on the formation of double-2DEG in AlGaAs/GaAs heterostructures. Journal of Vacuum Science and Technology B, 34, 2L110-1.

Droopad, R. (2016). Structural and optical properties of beta-Ga2O3 thin films grown by plasma-assisted molecular beam epitaxy. Journal of Vacuum Science and Technology B, 34, 02L109-1.

Droopad, R. (2016). Study of InAlAs/InGaAs self-switching diodes for energy harvesting applications. Japanese Journal of Applied Physics, 55, 014304.

Cortes-Mestizo, I., Méndez-García, V. H., Briones, J., Perez-Caro, M., Droopad, R., McMurtry, S., … Briones, E. (2015). Terahertz harvesting with shape-optimized InAlAs/InGaAs self-switching nanodiodes. AIP Advances, 5.

Kent, T., Tang, K., Chobpattana, V., Negara, M. A., Edmonds, M., Mitchell, W., … Kummel, A. C. (2015). The influence of surface preparation on low temperature HfO2 ALD on InGaAs (001) and (110) surfaces. J. of Chem. Phys, 143.

Bhatnagar, K., Caro, M. P., Rojas-Ramirez, J. S., Droopad, R., Thomas, P. M., Gaur, A., … Rommel, S. L. (2015). Integration of broken-gap heterojunction InAs/GaSb Esaki tunnel diodes on silicon. J.Vac. Sci. & Technol, B 33.

Qiao, Q., Zhang, Y., Contreras-Guerrero, R., Droopad, R., Pantelides, S. T., Pennycook, S. J., … Klie, R. F. (2015). Direct observation of oxygen-vacancy-enhanced polarization in a SrTiO3-buffered ferroelectric BaTiO3 film on GaAs. Appl. Phys. Letts, 107.

Tang, K., Winter, R., Zhang, L., Droopad, R., Eizenberg, M., & McIntyre, P. C. (2015). Border trap reduction in Al2O3/InGaAs gate stacks. Appl. Phys. Letts, 107.

Growden, T. A., Brown, E. R., Zhang, W., Droopad, R., & Berger, P. R. (2015). Experimental determination of quantum-well lifetime effect on large-signal resonant tunneling diode switching time. Appl. Phys. Letts, 107.

Wang, S. W., Vasen, T., Doornbos, G., Oxland, R., Chang, S. W., Li, X., … Passlack, M. (2015). Field-Effect Mobility of InAs Surface Channel nMOSFET With Low D-it Scaled Gate-Stack. IEEE Trans. Electron. Devices, 62.

Performance Evaluation of In0.53Ga0.47As Esaki Tunnel Diodes on Silicon and InP Substrates, P., Filmer, M., Gaur, A., Pawlik, D. J., Romanczyk, B., Marini, E., … Droopad, R. (2015). Performance Evaluation of In0.53Ga0.47As Esaki Tunnel Diodes on Silicon and InP Substrates. IEEE Trans. Electron. Devices, 62.

Edmonds, M., Kent, T., Chagarov, E., Sardashti, K., Droopad, R., Chang, M., … Kummel, A. (2015). Passivation of InGaAs(001)-(2 x 4) by Self-Limiting Chemical Vapor Deposition of a Silicon Hydride Control Layer. J. Am. Chem. Soc, 137.

Kent, T., Chagarov, E., Edmonds, M., Droopad, R., & Kummel, A. C. (2015). Dual Passivation of Intrinsic Defects at the Compound Semiconductor/Oxide Interface Using an Oxidant and a Reductant. ACS Nano, 9.

Gaur, A., Filmer, M., Thomas, P., Bhatnagar, K., Droopad, R., & Rommel, S. (2015). Fabrication and characterization of sub-micron In0.53Ga0.47As p-i-n diodes. Solid State Electronics, 111, 234–237.

Gatabi, J., Lyon, K., Rahman, S., Caro, M., Rojas-Ramirez, J., Cott-Garcia, J., … Lee, B. (2015). Functional materials integrated on III–V semiconductors. Microelectronic Engineering, 147, 117–121.

Bhatnagar, K., Rojas-Ramirez, J., Caro, M., Contreras, R., Henninger, B., & Droopad, R. (2015). In-situ monitoring during MBE growth of InAs based heterostructures. Journal of Crystal Growth, 425, 16–20.

Rojas-Ramirez, J. S., Wang, S., Contreras-Guerrero, R., Caro, M., Bhatnagar, K., Holland, M., … Droopad, R. (2015). AlxIn1−xAsySb1−y alloys lattice matched to InAs(1 0 0) grown by molecular beam epitaxy. Journal of Crystal Growth, 425, 33–38.

Bhatnagar, K., Rojas-Ramirez, J. S., Contreras-Guerrero, R., Caro, M., & Droopad, R. (2015). Heterointegration of III– V on silicon using a crystalline oxide buffer layer. Journal of Crystal Growth, 425, 262–267.

Cusco, R., Domenech-Amador, N., Hung, P. Y., Wei-Yip, L., Droopad, R., & Artus, L. J. (2015). Raman scattering study of LO phonon-plasmon coupled modes in p-type InGaAs. Alloys and Compounds, 634.

Gaur, A., Manwaring, I., Filmer, M. J., Thomas, P. M., Rommel, S. L., Bhatnagar, K., & Droopad, R. (2015). Surface treatments to reduce leakage current in In0.53Ga0.47As p-i-n diodes. J. Vac. Sci Tech, B33.

Peralagu, U., Povey, I. M., Carolan, P., Lin, J., Contreras-Guerrero, R., Droopad, R., … Thayne, I. G. (2014). Electrical and physical characterization of the Al2O3/p-GaSb interface for 1%, 5%, 10%, and 22% (NH4)(2)S surface treatments. Appl. Phys. Lett, 105.

Passlack, M., Wang, S.-W., Doornbos, G., Wang, C.-H., Contreras-Guerrero, R., Edirisooriya, M., … Diaz, C. H. (2014). Lifting the off-state bandgap limit in InAs channel metal-oxide-semiconductor heterostructures of nanometer dimensions. Appl. Phys. Letts, 104.

Majumdar, K., Thomas, P., Loh, W.-Y., Hung, P.-Y., Matthews, K., Pawlik, D., … Kirsch, P. D. (2014). Mapping Defect Density in MBE Grown In0.53Ga0.47As Epitaxial Layers on Si Substrate Using Esaki Diode Valley Characteristics. IEEE Trans. Electron Devices, 61.

Wang, C. H., Doornbos, G., Astromskas, G., Vellianitis, G., Oxland, R., Holland, M. C., … Diaz, C. H. (2014). High-k dielectrics on (100) and (110) n-InAs: Physical and electrical characterizations. AIP Advances, 4.

Bhuwalka, K. K., Wang, S. W., Noriega, O. C., Holland, M. C., Contreras-Guerrero, R., Edirisooriya, M., … Diaz, C. H. (2014). Comparative Study of High-k/GaSb Interfaces for Use in Antimonide Based MOSFETs. IEEE Electron Device Letters, 35.

Kent, T. J., Edmonds, M., Chagarov, E., Droopad, R., & Kummel, A. C. (2013). Dual passivation of GaAs (110) surfaces using O-2/H2O and  trimethylaluminum. J. of  Chemical Physics, 139.

Wang, C. H., Wang, S. W., Doornbos, G., Astromskas, G., Bhuwalka, K., Contreras-Guerrero, R., … Diaz, C. H. (2013). InAs hole inversion and bandgap interface state density of 2x1011 cm-2eV-1 at HfO2/InAs interfaces. Appl. Phys Letts, 103.

Contreras-Guerrero, R., Veazey, J. P., Levy, J., & Droopad, R. (2013). Properties of epitaxial BaTiO3 deposited on GaAs. Appl Phys Letts, 102.

Contreras-Guerrero, R., Edirisooriya, M., Noriega, O. C., & Droopad, R. (2013). Interface properties of MBE grown epitaxial oxides on GaAs. Journal of Crystal Growth, 378, 238–242.

Contreras-Guerrero, R., Wang, S., Edirisooriya, M., Priyantha, W., Rojas-Ramirez, J. S., Bhuwalka, K., … Droopad, R. (2013). Growth of heterostructures on InAs for high mobility device applications. Journal of Crystal Growth, 378, 117–120.

Lei, M., Price, J., Wang, W.-E., Wong, M. H., Droopad, R., Kirsch, P., … Downer, M. C. (2013). Characterization of anti-phase boundaries in hetero-epitaxial polar-on-nonpolar semiconductor films by optical second-harmonic generation. Appl Phys Letts, 102.

Laughlin, R. P., Currie, D. A., Contreras-Guererro, R., Dedigama, A., Priyantha, W., Droopad, R., … Pan, X. (2013). Magnetic and structural properties of BiFeO3 thin films grown epitaxially on SrTiO3/Si substrates. J. Appl. Phys, 113.

Droopad, R., Contreras-Guerrero, R., Veazey, J. P., Qiao, Q., Klie, R. F., & Levy, J. (2013). Epitaxial ferroelectric oxides on semiconductors- A route towards negative capacitance devices. Microelectronic Engineering, 109, 290–293.

Ramvall, P., Wang, C. H., Astromskas, G., Vellianitis, G., Holland, M., Droopad, R., … Diaz, C. H. (2013). MOVPE-grownInAs/AlAs0.16Sb0.84/InAs and InAs/AlAs0.16Sb0.84/GaSb heterostructures. Journal of Crystal Growth, 374, 43–48.

Priyantha, W., Droopad, R., Kopczyk, M., Smith, R. J., & Kayani, A. (2012). Structure of V thin films on Al(100) using XPD, LEED, and LEIS. Surface Science, 606, 1160–1166.

Melitz, W., Clemens, J. B., Shen, J., Chagarov, E. A., Lee, S., Lee, J. S., … Kummel, A. C. (2012). Scanning probe microscopy imaging before and after atomic layer oxide deposition on a compound semiconductor surface. Solid State Phenomena, 187, 9–10.

Kirsch, P. D., Hill, R. J. W., Huang, J., Loh, W. Y., Kim, T.-W., Wong, M. H., … Jammy, R. (2012). Challenges of III-V materials in advanced CMOS logic. Proceedings of the 2012 International Symposium on VLSI Technology, Systems and Application (VLSI-TSA), 2.

Melitz, W., Kent, T., Kummel, A., Droopad, R., Holland, M., & Thayne, I. (2012). Atomic imaging of atomic layer deposition oxide nucleation with trimethylaluminum on As-rich InGaAs(001) 2 × 4 vs In-rich InGaAs(001) 4 × 2. Journal of Chemical Physics, 136.

Hill, R. J. W., Huang, J., Loh, W. Y., Kim, T., Wong, M. H., Veksler, D., … Jammy, R. (2012). Integration challenges of III-V materials in advanced CMOS logic. ECS Transactions, 45, 179–184.

Melitz, W., Shen, J., Kent, T., Droopad, R., Hurley, P., & Kummel, A. C. (2011). Atomic imaging of atomic H cleaning of InGaAs and InP for ALD. ECS Transactions, 35, 175–189.

Pandey, R. K., Stapleton, W. A., Tate, J. S., Droopad, R., Sutanto, I., & Sprissler, S. (2011). Supercapacitor CCTO for High Energy Density Storage.

Wilhelm, M., Jian, S., Tyler, K., Kummel, A. C., & Droopad, R. (2011). InGaAs surface preparation for atomic layer deposition by hydrogen cleaning and improvement with high temperature anneal. Journal of Applied Physics, 110.

Priyantha, W., Radhakrishnan, G., Droopad, R., & Passlack, M. (2011). In-situ XPS and RHEED study of gallium oxide on GaAs deposition by molecular beam epitaxy. Journal of Crystal Growth, 323, 103–106.

Shen, J., Feldwinn, D., Melitz, W., Droopad, R., & Kummel, A. C. (2011). Scanning tunneling microscopy study of the interfacial bonding structures of Ga(2)O and In(2)O/In(0.53)Ga(0.47)As(001). Microelectronic Engineering, 88, 377–382.

Dong, L., Liu, Y. Q., Xu, M., Wu, Y. Q., Colby, R., Stach, E. A., … Ye, P. D. (2010). IEDM - TECHNICAL DIGEST  Book Series: International Electron Devices Meeting.

Shen Jian, M., Wilhelm, L., Sangyeob, F., Darby, L., Droopad, R., & Kummel, A. C. (2010). Interfacial atomic bonding structure of oxides on InAs (001) - (4x2) surface. Journal of the Electrochemical Society, 157, H1148–H1152.

Clemens, J. B., Chagarov, E. A., Holland, M., Droopad, R., Shen, J., & Kummel, A. C. (2010). Atomic imaging of the monolayer nucleation and unpinning of a compound semiconductor surface during atomic layer deposition. Journal of Chemical Physics, 133, 154–704.

Shen, J., Chagarov, E. A., Feldwinn, D. L., Melitz, W., Santagata, N. M., Kummel, A. C., … Passlack, M. (2010). Scanning tunneling microscopy/spectroscopy study of atomic and electronic structures of In2O on InAs and In0.53Ga0.47As (001- (4x2) surfaces. J. Chem. Phys, 133, 164–704.

Shen, J., Melitz, W., Feldwinn, D. L., Lee, S., Droopad, R., & Kummel, A. C. (2010). Bonding Geometries at the In2O and SiO/III-V Semiconductor Interface. ECS Transactions, 33, 105–116.

Clemens, J. B., Droopad, R., & Kummel, A. C. (2010). Reversible and irreversible reactions of three oxygen precursors on InAs(0 0 1)-(4×2)/c(8×2). Surface Science, 604, 1859–1868.

Passlack, M., Droopad, R., & Brammertz, G. (2010). Suitability Study of Oxide/Gallium Arsenide Interfaces for MOSFET Applications. IEEE Trans. on Electron Devices, 57, 2944–2956.

Shen, J., Clemens, J. B., Chagarov, E. A., Feldwinn, D. L., Melitz, W., Song, T., … Droopad, R. (2010). Structural and electronic properties of group III Rich In0.53Ga0.47As(001). Surface Science, 604, 1757–1766.

Melitz, W., Shen, J., Lee, S., Lee, J. S., Kummel, A. C., Droopad, R., & Yu, E. T. (2010). Scanning tunneling spectroscopy and Kelvin probe force microscopy investigation of Fermi energy level pinning mechanism on InAs and InGaAs clean surfaces. J. Appl. Phys, 108.

Clemens, J. B., Bishop, S. R., Lee, J. S., Kummel, A. C., & Droopad, R. (2010). Initiation of a passivated interface between hafnium oxide and In(Ga)As(0 0 1)-(4 × 2). Journal of Chemical Physics, 132.

Feldwinn, D. L., Clemens, J. B., Shen, J., Bishop, S. R., Grassman, T. J., Kummel, A. C., … Passlack, M. (2009). Anomalous hybridization in the In-rich InAs(0 0 1) reconstruction. Surface Science, 603, 3321–3328.

Thayne, I. G., Hill, R. J. W., Holland, M. C., Li, X., Zhou, H., Macintyre, D. S., … Passlack, M. (2009). Review of Current Status of III-V MOSFETs. ECS Transactions, 19, 275–286.

Clemens, J. B., Bishop, S. R., Feldwinn, D. L., Droopad, R., & Kummel, A. C. (2009). Initial stages of the autocatalytic oxidation of the InAs(001)-(4 x 2)/c(8 x 2) surface by molecular oxygen. Surface Science, 603, 2230–2239.

Passlack, M., Droopad, R., Fejes, P., & Wang, L. Q. (2009). Electrical Properties of Ga2O3/GaAs Interfaces and GdGaO Dielectrics in GaAs-Based MOSFETs. IEEE Electron Device Letts, 30, 2–4.

Passlack, M., Droopad, R., Feyes, P., & Wang, L. (2009). Electrical Properties of Ga2O3/GaAs Interfaces and GdGaO Dielectrics in GaAs-Based MOSFETs. IEEE Electron Device Letts, 30, 2–4.

Passlack, M., Droopad, R., Yu, Z., Medendorp, N., Braddock, D., Wang, X. W., … Buyuklimanli, T. (2008). Screening of Oxide/GaAs Interfaces for MOSFET Applications. IEEE Electron Device Letts, 29, 1181–1183.

Triyoso, D. H., Gilmer, D. C., Jiang, J., & Droopad, R. (2008). Characteristics of thin lanthanum lutetium oxide high-k dielectrics. Microelectronic Engineering, 85, 1732–1735.

Passlack, Droopad, R., Thayne, I., & Asenov, A. (2008). III-V MOSFETs for future CMOS applications. Solid State Technology.

Hill, R. J. W., Moran, D. A. J., Li, X., Zhou, H., Macintyre, D., Thoms, S., … Thayne, I. G. (2007). Enhancement-Mode GaAs MOSFETs With an In0.3Ga0.7As Channel, a Mobility of Over 5000 cm2/V s, and Transconductance of Over 475 μS/μm. IEEE Electron. Dev. Lett, 28, 1080–1082.

Winn, D. L., Hale, M. J., Grassman, T. J., Sexton, J. Z., Kummel, A. C., Passlack, M., & Droopad, R. (2007). Electronic properties of adsorbates on GaAs(001)-c(2x8)/(2x4). J. Chem. Phys, 127.

Rajagopalan, K., Droopad, R., Abrokwah, J., Zurcher, P., Fejes, P., & Passlack, M. (2007). 1-μm Enhancement Mode GaAs N-Channel MOSFETs With Transconductance Exceeding 250 mS/mm. IEEE Electron. Dev. Lett, 22, 100–102.

Kalna, K., Wilson, J., Moran, D., Moran, R., Long, A., Droopad, R., … Asenov, A. (2007). Monte Carlo Simulations of High-Performance Implant Free In0.3Ga0.7As Nano-MOSFETs for Low-Power CMOS Applications. IEEE Trans. Nanotechnology, 6, 106–112.

Rajagopalan, K., Abrokwah, J., Droopad, R., & Passlack, M. (2007). Enhancement mode high mobility n-MOSFET on gallium arsenide substrate. Phys. Stat. Sol, 4, 1671–1674.

Droopad, R., Rajagopalan, K., Abrokwah, J., Adams, L., England, N., Uebelhoer, D., … Passlack, M. (2007). Development of GaAs-based MOSFET using molecular beam epitaxy. Journal of Crystal Growth, 301–302, 139–144.

Winn, D. L., Hale, M. J., Grassman, T. J., CKummel, A. C., Droopad, R., & Matthias  Passlack, M. (2007). Direct and indirect causes of Fermi level pinning at the SiO∕GaAs interface. The Journal of Chemical Physics, 126.

Hill, R. J. W., Moran, D. A. J., Li, X., Zhou, H., Macintyre, D., Thoms, S., … Thayne, I. G. (2007). 180nm metal gate, high-k dielectric,implant-free III–V MOSFETs with transconductance of over 425 μS/μm. Electronics Letts, 43, 543–545.

Droopad, R., Rajagopalan, K., Abrokwah, J., Zurcher, P., & Passlack, M. (2007). Compound semiconductor MOSFETs. Microelectronic Engineering, 84, 2138–2141.

Droopad, R., Rajagopalan, K., Abrokwah, J., & Passlack, M. (2006). Gate dielectrics on compound semiconductors by molecular beam epitaxy. J. Vac. Sci Technol, B24, 1479–1482.

Droopad, R., Rajagopalan, K., Rajagopalan, J., Canonico, M., & Passlack, M. (2006). In0.75Ga0.25As channel layers with record mobility exceeding 12,000 cm2/Vs for use in high-k dielectric NMOSFETs. Solid State Electronics, 50, 1175.

Passlack, M., Rajagopalan, K., Abrokwah, J., & Droopad, R. (2006). Implant-Free high-Mobility Flatband MOSFET: Principles of Operation. IEEE Trans. Elect. Dev, 53.

Rajagopalan, K., Abrokwah, J., Droopad, R., & Passlack, M. (2006). Enhancement-Mode GaAs n-Channel MOSFET. IEEE Electron. Dev. Lett, 27, 959–962.

Passlack, M., Droopad, R., Rajagopalan, K., Abrokwah, J., Zurcher, P., & Fejes, P. (2006). High mobility III-V MOSFET technology. IEEE Cat, 4.

Paterson, G. W., Wilson, J. A., Moran, D., Hill, R., Long, A. R., Thayne, I., … Droopad, R. (2006). Gallium oxide (Ga2 O3) on gallium arsenide-A low defect, high-K system for future devices. Materials Science & Engineering B, 135, 277–281.

Droopad, R., Passlack, M., England, N., Rajagopalan, K., Abrokwah, J., & Kummel, A. (2005). Gate dielectrics on compound semiconductors. Microelectronic Engineering, 80, 138–145.

Passlack, M., Droopad, R., Rajagopalan, K., Abrokwah, J., Gregory, R., & Nguyen, D. (2005). High Mobility NMOSFET Structure with High-k Dielectric. IEEE Electron. Dev. Lett, 26, 713–715.

Woicik, J. C., Aguirre-Tostada, F. S., Herrera-Gomez, A., Droopad, R., Yu, Z., Schlom, D., … Pianetta, P. (2005). X-ray absorption fine-structure determination of interfacial polarization in SrTiO3 thin films grown on Si(001). Physica Scripta, 3.

Hale, M. J., Winn, S. L., Grassman, T. J., Kummel, A. C., & Droopad, R. (2005). Chemically resolved scanning tunneling microscopy imaging of Al on p-type AlGaAs(001) c(2×8)∕(2×4). The Journal of Chemical Physics,.

Yang, S. Y., Liu, B. T., Ouyang, J., Nagarajan, V., Kulkarni, V. N., Ramesh, R., … Eisenbeiser, K. (2005). Epitaxial Pb(Zr,Ti)O/sub 3/ capacitors on Si by liquid delivery metalorganic chemical vapor deposition. Journal of Electroceramics, 14, 37–44.

Droopad, R., Eisenbeiser, K., & Demkov, A. A. (2004). High Dielectric Constant Materials- VLSI MOSFET Applications. In Springer (Ed.), High-K Crystalline Gate Dielectrics – An IC Manufacturer’s Perspective.

Aguirre-Tostado, F. S., Herrera-Gómez, A., Woicik, J. C., Droopad, R., Yu, Z., Schlom, D. G., … Hellberg, C. S. (2004). Elastic anomaly for SrTiO3 thin films grown on Si(001). PHYSICAL REVIEW B, 70.

Wang, J., Zheng, H., Ma, Z. `, Prasertchoung, S., Wuttig, M., Droopad, R., … Ramesh, R. (2004). Epitaxial BiFeO/sub 3/ thin films on Si. Applied Physics Letters, 85, 2574–2576.

Liang, Y., Wei, Y., Hu, X. M., Yu, Z., Droopad, R., Li, H., & Moore, K. (2004). Heteroepitaxy of SrTiO/sub 3/ on vicinal Si(001): growth and kinetic effects. Journal of Applied Physics, 96, 3413–3416.

Liang, Y., Kulik, J., Eschrich, T. C., Droopad, R., Yu, Z., & Maniar, P. (2004). Hetero-epitaxy of perovskite oxides on GaAs(001) by molecular beam epitaxy. Applied Physics Letters, 85, 1217–1219.

Aguirre-Tostado, F. S., Herrera-Gomez, A., Woicik, J. C., Droopad, R., Yu, Z., Schlom, D. G., … Pianetta, P. (2004). Displacive phase transition in SrTiO/sub 3/ thin films grown on Si(001). Journal of Vacuum Science & Technology A (Vacuum, Surfaces, and Films), 22, 1356–1360.

Kim, B. M., Brintlinger, T., Cobas, E., Fuhrer, M. S., Zheng, H., Yu, Z., … Eisenbeiser, K. (2004). High-performance carbon nanotube transistors on SrTiO/sub 3//Si substrates. Applied Physics Letters, 84, 1946–1948.

Zhao, T., Ogale, S. B., Shinde, S. R., Ramesh, R., Droopad, R., Yu, J., … Misewich, J. (2004). Colossal magnetoresistive manganite-based ferroelectric field-effect transistor on Si. Applied Physics Letters, 85, 750–752.

Ginley, D., Guha, S., Carter, S., Chambers, S. A., Droopad, R., Hosono, H., … Tate, J. (Eds.). (2003). Crystalline Oxide-Silicon Heterostructures and Oxide Optoelectronics (Vol. 747). Warrendale: Materials Research Society.

Passlack, M., Yu, Z., Droopad, R., Abrokwah, J., Braddock, D., Yi, S., … Kummel, A. (2003). III-V Semiconductor Heterostructures: Physics and Devices. In Gallium Oxide on Gallium Arsenide: Atomic Structure, Materials and Devices. Research Signpost.

Droopad, R., Zhiyi, Y., Hao, L., Liang, Y., Overgaard, C., Demkov, A., … Finder, J. (2003). Development of integrated heterostructures on silicon by MBE. Journal of Crystal Growth, 251, 638–644.

Eisenbeiser, K., Droopad, R., Yu, Z., Overgaard, C., Kulik, J., Finder, J., … Penunuri, D. (2003). Crystalline Oxide-based Devices on Silicon Substrate. J. Electronic Materials, 32, 868–871.

Yu, Z., Overgaard, C. D., Droopad, R., Passlack, M., & Abrokwah, J. K. (2003). Growth and physical properties of Ga/sub 2/O/sub 3/ thin films on GaAs(001) substrate by molecular-beam epitaxy. Applied Physics Letters, 82, 2978–2980.

Droopad, R., Curless, J., Yu, Z., Jordan, D., Liang, Y., Overgaard, C., … Baklenov, O. (2003). GaAs on silicon Using an Oxide Buffer Layer. Inst. Phys. Conf, Ser, 1–8.

`Yu, Z., Liang, Y., Hi, H., Curless, J., Overgaard, C., Droopad, R., … Moore, K. (2003). Progress in epitaxial oxides on semiconductors. Crystalline Oxide-Silicon Heterostructures and Oxide Optoelectronics, 747, 31–42.

Li, H., Hu, X., Wei, Y., Yu, Z., Zhang, X., Droopad, R., … Fejes, P. (2003). Two-dimensional growth of high-quality strontium titanate thin films on Si. Journal of Applied Physics, 93, 4521–4525.

Passlack, M., Abrokwah, J. K., Yu, Z., Droopad, R., Overgaard, C., & Kawayoshi, H. (2003). Thermally induced oxide crystallinity and interface destruction in Ga/sub 2/O/sub 3/-GaAs structures. Applied Physics Letters, 82, 1691–1693.

Xiaoming, H., Li, H., Liang, Y., Wei, Y., Yu, Z., Marshall, D., … Kulik, J. (2003). The interface of epitaxial SrTiO/sub 3/ on silicon: in situ and ex situ studies. Applied Physics Letters, 82, 203–205.

Wei, Y., Hu, X., Liang, Y., Jordan, D. C., Craigo, B., Droopad, R., … Ooms, W. J. (2002). Mechanism of cleaning Si(100) surface using Sr or SrO for the growth of crystalline SrTiO3 films. Journal of Vacuum Science & Technology B (Microelectronics and Nanometer Structures), 20, 1402–1405.

Wei, Y., Hu, X., Liang, Y., Jordan, D. C., Craigo, B., Droopad, R., … Ooms, W. J. (2002). Si(100) surface cleaning using Sr and SrO. Silicon Materials - Processing, Characterization and Reliability Symposium (Mater. Res. Soc. Proceedings, 716, 139–144.

Hu, X., Liang, Y., Wei, Y., Edwards Jr, J. L., Droopad, R., Moore, K., & Ooms, W. J. (2002). Sr/Si template formation for the epitaxial growth of SrTiO/sub 3/ on silicon. Silicon Materials - Processing, Characterization and Reliability Symposium, 716, 261–266.

Droopad, R., Curless, J. A., Yu, Z., Jordan, D. c, Liang, Y., Overgaard, C. D., … Prendergast, J. (2002). Development of integrated heterostructures on silicon by MBE. 2002 International Conference on Molecular Beam Epitaxy (Cat. No.02EX607), 45–46.

Nagarajan, V., Stanishevsky, A., Chen, L., Zhao, T., Liu, B. T., Melngailis, J., … Eisenbeiser, K. (2002). Realizing intrinsic piezoresponse in epitaxial submicron lead zirconate titanate capacitors on Si. Applied Physics Letters, 81, 4215–4217.

Eisenbeiser, K., Droopad, R., & Finder, J. (2002). New research yields epitaxially grown GaAs on Si. Solid State Technology, 45, 61–62, 64, 67.

Passlack, M., Abrokwah, J. K., Droopad, R., Zhiyi, Y., Overgaard, C., Yi, S. I., … Kummel, A. C. (2002). Self-aligned GaAs p-channel enhancement mode MOS heterostructure field-effect transistor. IEEE Electron Device Letters, 23, 508–510.

Liu, R., Zollner, S., Fejes, P., Gregory, R., Lu, S., Reid, K., … Eisenbeiser, K. (2002). Materials and physical properties of novel high-k and medium-k gate dielectrics. Gate Stack and Silicide Issues in Silicon Processing II, 670, 1–12.

Z Yu, Droopad, R., Jordan, D., Curless, J., Liang, Y., Overgaard, C., … Tisinger, L. (2002). GaAs-based heterostructures on silicon. Digest of Papers, 276–279.

Shutthanandan, V., Thevuthasan, S., Liang, Y., Adams, E. M., Yu, Z., & Droopad, R. (2002). Direct observation of atomic disordering at the SrTiO/sub 3//Si interface due to oxygen diffusion. Applied Physics Letters, 80, 1803–1805.

Eisenbeiser, K., Emrick, R., Droopad, R., Yu, Z., Finder, J., Rockwell, S., … Ooms, W. (2002). GaAs MESFETs fabricated on Si substrates using a SrTiO/sub 3/ buffer layer. IEEE Electron Device Letters, 23, 300–302.

Browne, R. J., Ogryzlo, E. A., Eisenbeiser, K., Yu, Z., Droopad, R., & Overgaard, C. (2002). Passivation of defects at the SrTiO/sub 3//Si interface with H and H/sub 2/. Applied Physics Letters, 80, 2699–2700.

Yang, G. Y., Finder, J. M., Wang, J., Wang, Z. L., Yu, Z., Ramdani, J., … Ramesh, R. (2002). Study of microstructure in SrTiO/sub 3//Si by high-resolution transmission electron microscopy. Journal of Materials Research, 17, 204–213.

Wang, Y., Ganpule, C., Liu, B. T., Li, H., Mori, K., Hill, B., … Eisenbeiser, K. (2002). Epitaxial ferroelectric Pb(Zr, Ti)O/sub 3/ thin films on Si using SrTiO/sub 3/ template layers. Applied Physics Letters, 80, 97–99.

Liu, R., Zollner, S., Fejes, P., Gregory, R., Lu, S., Reid, K., … Hobbs, C. C. (2002). Materials and physical properties of novel high-k and medium-k gate dielectrics. Materials Research Society Symposium Proceedings, 670, K1.1.1-12.

Herrera-Gómez, A., Aguirre-Tostado, F. S., Sun, Y., Pianetta, P., Yu, Z., Marshall, D., … Spicer, W. E. (2001). Photoemission from the Sr/Si(001) interface. Journal of Applied Physics, 90(12), 6070–6072.

Droopad, R., Yu, Z., Ramdani, J., Hilt, L., Curless, J., Overgaard, C., … Ooms, B. (2001). Epitaxial oxides on silicon by molecular beam epitaxy. J. Crystal Growth, 227–228, 936–943.

Droopad, R., Yu, Z., Ramdani, J., Hilt, L., Curless, J., Overgaard, C., … Ooms, W. (2001). Development of high dielectric constant epitaxial oxides on silicon by molecular beam epitaxy. Materials Science & Engineering B (Solid-State Materials for Advanced Technology), B87, 292–296.

Hu, X., Yu, Z., Curless, J. A., Droopad, R., Eisenbeiser, K., Edwards Jr., J. L., … Sarid, D. (2001). Comparative study of Sr and Ba adsorption on Si(100). Applied Surface Science, 181, 103–110.

Chambers, S. a, Liang, Y., Yu, Z., Droopad, R., & Ramdani, J. (2001). Band offset and structure of SrTiO3 /Si(001) heterojunctions. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 19(3), 934–939.

Zollner, S., Demkov, A. A., Liu, R., Curless, J. A., Yu, Z., Ramdani, J., & Droopad, R. (2000). Optical properties of thin-film SrTiO/sub 3/ on Si grown by MBE. Recent Developments in Oxide and Metal Epitaxy - Theory and Experiment, 619, 167–171.

Droopad, R., Wang, J., Eisenbeiser, K., Yu, Z., Ramdani, J., Curless, J. A., … Ooms, W. J. (2000). Epitaxial oxide films on silicon: growth, modeling and device properties. Recent Developments in Oxide and Metal Epitaxy - Theory and Experiment, 619, 155–165.

Chambers, S. A., Liang, Y., Yu, Z., Droopad, R., Ramdani, J., & Eisenbeiser, K. (2000). Band discontinuities at epitaxial SrTiO3/Si(001) heterojunctions. Applied Physics Letters, 77(11), 1662–1664.

Zollner, S., Demkov, A. A., Liu, R., Fejes, P. L., Gregory, R. B., Alluri, P., … Woollam, J. A. (2000). Optical properties of bulk and thin-film SrTiO3 on Si and Pt. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 18(4), 2242–2254.

Yu, Z., Ramdani, J., Curless, J. A., Overgaard, C. D., Finder, J. M., Droopad, R., … `Kaushik, V. S. (2000). Epitaxial oxide thin films on Si(001). Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 18(4), 2139–2145.

Ramdani, J., Droopad, R., Yu, Z., Curless, J. A., Overgaard, C. D., Finder, J., … Pietambaram, S. (2000). Interface characterization of high-quality SrTiO/sub 3/ thin films on Si(100) substrates grown by molecular beam epitaxy. Applied Surface Science, 159–160, 127–133.

Hu, X., Yao, X., `Peterson, C. A., Sarid, D., Yu, Z., Wang, J., … Ooms, W. J. (2000). Barium adsorption on Si(100)-(2*1) at room temperature: a bi-polar scanning tunneling microscopy study. Surface Science, L391-6.

Yu, Z., Ramdani, J., Curless, J. A., Finder, J. M., Overgaard, C. D., Droopad, R., … Kaushik, V. S. (2000). Epitaxial perovskite thin films grown on silicon by molecular beam epitaxy. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 18(3), 1653–1657.

Eisenbeiser, K., Finder, J. M., Yu, Z., Ramdani, J., Curless, J. A., Hallmark, J. A., … Overgaard, C. D. (2000). Field effect transistors with SrTiO3 gate dielectric on Si. Applied Physics Letters, 76(10), 1324–1326.

Hu, X., Yao, X., Peterson, C. A., Sarid, D., Yu, Z., Wang, J., … Ooms, W. J. (2000). The (3*2) phase of Ba adsorption on Si(001)-2*1. Surface Science, 445, 256–266.

Yu, Z., Droopad, R., Ramdani, J., Curless, J. A., Overgaard, C. D., Finder, J. M., … Hattori, T. (1999). Properties of epitaxial SrTiO/sub 3/ thin films grown on silicon by molecular beam epitaxy. Ultrathin SiO/Sub 2/ and High-K Materials for ULSI Gate Dielectrics, 427–433.

Hallmark, J., Zhiyi, Y., Droopad, R., Ramdani, J., Curless, J., Overgaard, C., … Ooms, B. (1999). Epitaxial BaTiO/sub 3/ films on silicon for MFSFFT applications. Integrated Ferroelectrics, 27, 41–50.

Eisenbeiser, K., Droopad, R., & Huang, J.-H. (1999). Metamorphic InAlAs/InGaAs enhancement mode HEMTs on GaAs substrates. IEEE Electron Device Letters, 20(10), 507–509.

Hu, X., Peterson, C. A., Sarid, D., Yu, Z., Wang, J., Marshall, D. S., … Ooms, W. J. (1999). Phases of Ba adsorption on Si(100)-(2*1) studied by LEED and AES. Surface Science, 426(1), 69–74.

Mathine, D. L., Maracas, G. N., Gerber, D. S., Droopad, R., Graham, R. J., & McCartney, M. R. (1999). Characterization of an AlGaAs/GaAs asymmetric triangular quantum well grown by a digital alloy approximation. Journal of Applied Physics, 75(9), 4551–4556.

Yao, X., Xiaoming, H., Sarid, D., Yu, Z., Wang, J., Marshall, D. S., … Ooms, W. J. (1999). Initial stages of Ba adsorption on the Si(100)-(2×1) surface at room temperature. Physical Review B (Condensed Matter and Materials Physics), 59(7), 5115–5119.

Passlack, M., Yu, Z., Droopad, R., Bowers, B., Overgaard, C., Abrokwah, J., & Kummel, A. C. (1999). Interface charge and nonradiative carrier recombination in Ga2O3-GaAs interface structures. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 17(1), 49–52.

Passlack, M., Droopad, R., Yu, Z., `Overgaard, C., Bowers, B., & Abrokwah, J. (1998). Nonradiative recombination at GaAs homointerfaces fabricated using an As cap deposition/removal process. Applied Physics Letters, 72(24), 3163–3165.

Passlack, M., Droopad, R., Yu, Z., Overgaard, C., Bowers, B., Abrokwah, J., … Reed, M. A. (1997). Electronic properties of MBE grown GaAs homointerfaces fabricated using the As cap deposition/removal technique. Compound Semiconductors 1997, 131–134.

Huang, J. H., Glass, E., Abrokwah, J., Bernhardt, B., Majerus, M., Spears, E., … Blaugh, J. (1997). Device and process optimization for a low voltage enhancement mode power heterojunction FET for portable applications. 19th Annual Technical Digest, 55–58.

Glass, E., Huang, J. H., Abrokwah, J., Bernhardt, B., Majerus, M., Spears, E., … Koepf, G. A. (1997). A true enhancement mode single supply power HFET for portable applications. 1997 IEEE MTT-S International Microwave Symposium Digest, 3, 1399–1402.

Mathine, D. L., Droopad, R., & Maracas, G. N. (1997). A vertical-cavity surface-emitting laser appliqued to a 0.8- mu m NMOS driver. IEEE Photonics Technology Letters, 9, 869–871.

Mathine, D. L., Nejad, H., Allee, D. R., Droopad, R., & Maracas, G. N. (1996). Reduction of the thermal impedance of vertical-cavity surface-emitting lasers after integration with copper substrates. Applied Physics Letters, 69(4), 463–464.

Moneger, S., Qiang, H., Pollak, F. H., Mathine, D. L., Droopad, R., & Maracas, G. N. (1996). Contactless electroreflectance characterization of three InGaAs quantum wells placed in a GaAs/AlGaAs resonant cavity. Solid-State Electronics, 39, 871–874.

Fathollahnejad, H., Daryanani, S., Mathine, D. L., Chuang, C. P., Droopad, R., & Maracas, G. N. (1995). The integration of GaAs vertical-cavity surface emitting lasers onto silicon circuitry. Proceedings. IEEE/Cornell Conference on Advanced Concepts in High Speed Semiconductor Devices and Circuits, 373–381.

Chau-Hong, K., Anand, S., Droopad, R., Mathine, D. L., Maracas, G. N., Johs, B., … Mishra, U. (1995). Real time monitoring of III-V alloy composition and real time control of quantum well thickness in MBE by multi-wavelength ellipsometry. Compound Semiconductors 1994. Proceedings of the Twenty-First International Symposium, 29–34.

Maracas, G. N., Kuo, C. H., Anand, S., Droopad, R., Sohie, G. R. L., & Levola, T. (1995). Ellipsometry for III-V epitaxial growth diagnostics,. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 13(3), 727–732.

Kuo, C. H., Anand, S., Fathollahnejad, H., Ramamurti, R., Droopad, R., & Maracas, G. N. (1995). Measurement of AlxGa1 - xAs temperature dependent optical constants by spectroscopic ellipsometry. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 13(2), 681–684.

Fathollahnejad, H., Rajesh, R., Liu, J., Droopad, R., Maracas, G. N., & Carpenter, R. W. (1995). Low resistance Pd/Ge ohmic contacts to epitaxially lifted-off n-type GaAs film. Journal of Electronic Materials, 24, 35–38.

Moneger, S., Pollak, F. H., Mathine, D. L., Droopad, R., & Maracas, G. N. (1994). Electroreflectance characterization of three InGaAs quantum wells placed in a GaAs/GaAlAs resonant cavity: contactless and contact modes (Vol. 2, pp. 218–219).

Yu, F., Droopad, R., Maracas, G. N., Liu, J., Rajesh, R., Carpenter, R. W., … Wicks, G. W. (1994). Electrical characterization of highly strained ultrathin InAs/GaAs quantum wells. Growth, Processing, and Characterization of Semiconductor Heterostructures. Symposium, 151–156.

Mathine, D. L., Fathollahnejad, H., Droopad, R., Daryanani, S., & Maracas, G. N. (1994). InGaAs quantum well vertical-cavity surface-emitting lasers integration onto silicon substrates (Vol. 1, pp. 282–283).

Spencer, G. S., Ho, A. C., Menéndez, J., Droopad, R., Fathollahnejad, H., & Maracas, G. N. (1994). Lattice-constant dependence of the dynamical effective charge in AlAs and GaAs. Physical Review B (Condensed Matter), 50(19), 14125–14130.

Fathollahnejad, H., Mathine, D. L., Droopad, R., Maracas, G. N., & Daryanani, S. (1994). Vertical-cavity surface-emitting lasers integrated onto silicon substrates by PdGe contacts. Electronics Letters, 30, 1235–1236.

Mathine, D. L., Maracas, G. N., Gerber, D. S., Droopad, R., Graham, R. J., & McCartney, M. R. (1994). Characterization of an AlGaAs/GaAs asymmetric triangular quantum well grown by a digital alloy approximation. Journal of Applied Physics, 75(9), 4551–4556.

Kuo, C. H., Anand, S., Droopad, R., Choi, K. Y., & Maracas, G. C. (1994). Measurement of GaAs temperature-dependent optical constants by spectroscopic ellipsometry. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 12(2), 1214–1216.

Droopad, R., Kuo, C. H., Anand, S., Choi, K. Y., & Maracas, G. N. (1994). Determination of molecular beam epitaxial growth parameters by ellipsometry. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 12(2), 1211–1213.

Kuo, C. H., Anand, S., Droopad, R., Choi, K. Y., & Maracas, G. N. (1994). Measurement of GaAs temperature-dependent optical constants by spectroscopic ellipsometry. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 12(2), 1214–1216.

Droopad, R., Kuo, C. H., Anand, S., Choi, K. Y., & Maracas, G. N. (1994). Determination of molecular beam epitaxial growth parameters by ellipsometry. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 12(2), 1211–1213.

Cody, J. G., Mathine, D. L., Droopad, R., Maracas, G. N., Rajesh, R., & Carpenter, R. W. (1994). Application of the digital alloy composition grading technique to strained InGaAs/GaAs/AlGaAs diode laser active regions. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 12(2), 1075–1077.

Grann, E. D., Sheih, S. J., Chia, C., Tsen, K. T., Sankey, O. F., Guncer, S. E., … Morkoç, H. (1994). Picosecond Raman studies of electric-field-induced nonequilibrium carrier distributions in GaAs-based p-i-n nanostructure semiconductors. Applied Physics Letters, 64(10), 1230–1232.

Spencer, G. S., Grant, J., Gray, R., Zolman, J., Menéndez, J., Droopad, R., & Maracas, G. N. (1994). Second-order Raman spectroscopy of AlAs: A test of lattice-dynamical models. Physical Review B (Condensed Matter), 49(8), 5761–5764.

Gerber, D. S., Droopad, R., & Maracas, G. N. (1993). A GaAs/AlGaAs Asymmetric Fabry-Perot Reflection Modulator with Very High Contrast Ratio. Photonics Technology Letts, 5, 55–58.

Droopad, R., Gerber, D. S., Choi, C., & Maracas, G. N. (1993). Pseudomorphic InGaAs/GaAs and GaAs/AlGaAs asymmetric triangular quantum wells grown by MBE for optoelectronic device applications. Journal of Crystal Growth, 127, 606–610.

Gerber, D. S., Droopad, R., & Maracas, G. N. (1993). Comparison of electroabsorption in asymmetric triangular and rectangular GaAs/AlxGa1 - xAs multiple quantum wells. Applied Physics Letters, 62(5), 525–527.

Puechner, R. A., Gerber, D. S., Droopad, R., & Maracas, G. N. (1992). Nonlinear Electroabsorption in Asymmetric Triangular Quantum Well Self-Electro Effect Devices. Journal of Nonlinear Optical Physics and Materials, 1(03), 473–491.

Park, C., Shiralagi, K. T., Droopad, R., & Maracas, G. N. (1992). A Novel Optically Bistable Multiple Quantum Well Phase Modulator. Photonics Technology Letts, 4, 1225–1227.

Maracas, G. N., Edwards, J. L., Shiralagi, K., Choi, K. Y., Droopad, R., Johs, B., & Woolam, J. A. (1992). In situ spectroscopic ellipsometry in molecular beam epitaxy. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 10(4), 1832–1839.

Goronkin, H., Shen, Ju., Tehrani, S., Droopad, R., Maracas, G. N., Legge, R. N., & Zhu, X. T. (1992). Enhancement of mobility in pseudomorphic FET’s with up and down monolayers. Japanese Journal of Applied Physics, Part 1, 31(0021–4922), 2071–2074.

Shen, J., Tehrani, S., Goronkin, H., Droopad, R., & Maracas, G. (1992). Quantum well thickness effect on the deep-shallow duality of Si in AlGaAs/InGaAs heterostructures. Journal of Applied Physics, 71(12), 5985–5988.

Droopad, R., Shiralagi, K. T., Puechner, R. A., Choi, K. Y., & Maracas, G. N. (1992). Low temperature GaAs grown by gas source molecular beam epitaxy. In Chemical beam epitaxy and related growth techniques 1991 (0022–0248 ed., Vol. 120, pp. 200–205).

Edwards, J. L., Maracas, G. N., Shiralagi, K. T., Choi, K. Y., & Droopad, R. (1992). In-situ and ex-situ characterization of GaAs/AlAs quantum well structures using spectroscopic ellipsometry. Journal of Crystal Growth, 120, 78–83.

Zhu, T. X., Goronkin, H., Maracas, G. N., Droopad, R., & Stroscio, M. A. (1992). Electron mobility enhancement by confining optical phonons in GaAs/AlAs multiple quantum wells. Applied Physics Letters, 60(17), 2141–2143.

Shiralagi, K. T., Choi, K. Y., Droopad, R., Maracas, G. N., & Quinn, W. E. (1992). Hydride cracker nozzle design for gas source molecular beam epitaxy. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 10(1), 46–50.

Adinall, R., Murray, R., Newman, R. C., Wagner, J., Parker, S. D., Williams, R. L., … Stradling, R. A. (1991). Local Vibrational Mode Spectroscopy of Si donors and Be Acceptors in MBE InAs and InSb Studied by Infrared Absorption and Raman Scattering. Semicond. Sci. & Tech, 6, 147–154.

Droopad, R., Puechner, R. A., Shiralagi, K. T., Choi, K. Y., & Maracas, G. N. (1991). Optical Properties of a Single Strained InGaAs/GaAs Quantum Well Grown on Vicinal GaAs Surfaces. Appl. Phys. Lett, 58(16), 1771–1779.

Puechner, R. A., Johnson, D. A., Shiralagi, K. T., Gerber, D. S., Droopad, R., & Maracas, G. N. (1991). Electrical and Optical Characterization of Gas Source and Solid Source MBE Low Temperature Buffers. J. Crystal Growth, 111, 43–49.

Shiralagi, K. T., Puechner, R. A., Choi, K. Y., Droopad, R., & Maracas, G. N. (1991). Optical Properties of Quantum Wells Grown Upon Gas Source Molecular Beam Epitaxy Low Temperature Buffers. J. Appl. Phys, 69, 7942–7944.

Droopad, R., Choi, K. Y., Puechner, R. A., Shiralagi, K. T., Gerber, D. s, & Maracas, G. N. (1991). Optical Properties of Strained Asymmetric Triangular InGaAs/GaAs Multiple Quantum Wells. Appl. Phys. Lett, 59, 2308–2310.

Droopad, R., Puechner, R. A., Choi, K. y, Shiralagi, K. T., & Maracas, G. N. (1991). Molecular Beam Epitaxial Growth and Optical Properties of Strained Rectangular and Asymmetric Triangular InGaAs Quantum Well Structures. J. Crystal Growth, 114, 327–336.

Johs, B., Edwards, J. L., Shiralagi, K. t, Droopad, R., Choi, K. Y., Maracas, G. N., … Aoyagi, Y. (1991). Real-time analysis of in-situ spectroscopic ellipsometric data during MBE growth of III-V semiconductors (pp. 75–80).

Shiralagi, K. T., Puechner, R. A., Choi, K. Y., Droopad, R., & Maracas, G. N. (1991). Narrow photoluminescence linewidth of quantum wells grown by gas source molecular beam epitaxy. Journal of Crystal Growth, 114, 337–345.

Goronkin, H., Tehrani, S., Droopad, R., Maracas, G. N., Shen, J., Legge, R. N., & Zhu, X. T. (1991). Enhancement of mobility in pseudomorphic FETs with up and down monolayers. IEEE Transactions on Electron Devices, 38, 2703.

Droopad, R., Puechner, R. A., Choi, K. Y., Shiralagi, K. T., & Maracas, G. N. (1991). Molecular beam epitaxial growth and optical properties of strained rectangular and asymmetric triangular InGaAs quantum well structures. Journal of Crystal Growth, 114(0022–0248), 327–336.

Puechner, R. a, Gerber, D. S., Johnson, D. A., Droopad, R., & Maracas, G. N. (1990). Optical Properties of Asymmetric Triangular Quantum Wells for Self Electro-optic Effect Devices. In Technical Digest (p. 115).

Evans, S. D., Cao, L. L., Egdell, R. G., Droopad, R., Parker, S. D., & Stradling, R. A. (1990). Protective Overlayer Techniques for Preparation of InSb(001) Surfaces. Surf. Sci, 226, 169–179.

Zhang, X., Staton-Bevan, A. E., Pashley, D. W., Parker, S. D., Droopad, R., Williams, R. L., & Newman, R. C. (1990). A TEM and RHEED Study of the Initial Stages of Heteroepitaxial Growth of InSb on GaAs. J. Appl. Physics, 67, 800–806.

Phillips, C. C., Hodge, C., Thomas, R., Parker, S. D., Williams, R. L., & Droopad, R. (1990). Nipi Superlattices in InSb: An Alternative Approach to 10µm  Detector Fabrication. In Semicond. Sci. Tech (Vol. 5, pp. S319–S322).

Williams, R. L., Skuras, E., Stradling, R. A., Droopad, R., Holmes, S. N., & Parker, S. D. (1990). MBE Growth and Quantum Transport Measurement of Spike Doped InSb and InAs. In Semicond. Sci. & Tech (Vol. 5, pp. S338–S341).

Seong, T. Y., Norman, A. G., Booker, G. R., Droopad, R., Williams, R. L., Parker, S. D., … Stradling, A. (1990). Atomic Ordering and Alloy Clustering in MBE Grown InAsSb Epilayers. In D. J. Wolford & J. Bernhols (Eds.), Impurities, Defects and Diffusion in Semiconductors: Bulk and Layered Structures, Materials Research Society Symposium Proceedings (Vol. 163, p. 900).

d’Oliveira, A., Parker, S. D., Droopad, R., & Joyce, B. A. (1990). A Generalised Model for the Reconstruction of {001} Surfaces of III-V Compound Semiconductors Based on a RHEED Study of InSb(001). Surf. Sci, 227, 150–156.

Wang, P. D., Holmes, S. N., Stradling, R. A., Droopad, R., Ferguson, I., d’Oliveira, A., … Williams, R. L. (1990). Far Infrared Magneto-optical Studies of Free and Bound Carriers in High Purity MBE InAs. Mat. Sci. Forum, 65–66, 381–388.

Droopad, R., Williams, R. L., & Parker, S. D. (1989). RHEED Intensity Oscillations observed during MBE Growth of InSb(001). Semicond. Sci. & Tech, 4, 111–113.

Holmes, S. N., Stradling, R. A., Wang, P. D., Droopad, R., Parker, S. D., & Williams, R. L. (1989). Magneto-optical and Transport Studies of Ultrahigh Mobility Films  of InAs Grown by Molecular Beam Epitaxy on GaAs. Semicond. Sci. & Tech, 4, 303–308.

Parker, S. D., Williams, R. L., Droopad, R., Stradling, R. A., Barnham, K. W. J., Holmes, S. N., … Pashley, D. W. (1989). Observation and Control of the Amphoteric Behaviour of Si-Doped InSb Grown on GaAs by  MBE. Semicond. Sci. & Tech, 4, 663–675.

Droopad, R., Parker, S. D., Skuras, E., Williams, R. L., Stradling, R. A., Beall, R. B., & Harris, J. J. (1989). Parallel and Perpendicular Field Magnetotransport Studies of MBE Grown GaAs Doping Superlattices and Slab Doped InSb Formed by Selective Doping with Silicon. High Magnetic Fields in Semiconductor Physics II, 199–206.

Holmes, S. N., Phillips, C. C., Stradling, R. a, Wasilewski, Z., Droopad, R., Parker, S. D., … Whitehouse, C. T. (1989). Residual Donor Contamination in MOCVD, MOMBE and MBE GaAs Studied by Far Infrared Spectroscopy. Semicond. Sci. & Tech, 4, 782–790.

Oxland, R., Chang, S. W., Li, X., Wang, S. W., Radhakrishnan, G., Priyantha, W., … Sun, Y. C. (1925). An ultra-low resistance, ultra-shallow, metallic source-drain contact scheme for III-V NMOS. IEEE Electron Device Letts, 33(4), 501–503.

Daryanani, S., Fathollahnejad, H., Mathine, D. L., Droopad, R., Kubes, A., & Maracas, G. N. (1925). Integration of a single vertical-cavity surface emitting laser onto a CMOS inverter chip. Electronics Letters, 31(0013–5194), 833–834.

Maracas, G. N., Kuo, C. h, Anand, S., & Droopad, R. (1925). Temperature-dependent pseudodielectric functions of GaAs determined by spectroscopic ellipsometry. Journal of Applied Physics, 77(0021–8979), 1701–1704.

Grann, E. D., Sheih, S. J., Chia, C., Tsen, K. T., Sankey, O. F., Maracas, G. N., … Morkoc. (1925). High-field electron transport in GaAs: a picosecond time-resolved Raman probe. In D. K. Ferry & H. M. van Driel (Eds.), Hadis Proc. SPIE (Vol. 2142, pp. 190–197).

Hao, Q., Pollak, F. H., Huang, Y. S., Chi, W. S., Droopad, R., Mathine, D. L., & Maracas, G. N. (1925). Photoreflectance study of GaAs/GaAlAs digital alloy compositionally graded structures. Quantum Well and Superlattice Physics V, 2139, 11–19.

Qiang, H., Pollak, F. H., Huang, Y. S., Chi, W. S., Droopad, R., Mathine, D. L., & Maracas, G. N. (1925). Photoreflectance study of GaAs/GaAlAs digital alloy compositionally graded structures. In G. H. Doehler & E. S. Koteles (Eds.), Quantum Well and Superlattice Physics V (Vol. 2139, pp. 11–19).

Maracas, G. N., Edwards, J. L., Shiralagi, K., Choi, K. Y., Droopad, R., Johs, B., & Woollam, J. A. (1925). In-situ spectroscopic ellipsometry in molecular beam epitaxy. In Nebraska Univ., Materials, Structures, and Devices for High-Speed Electronics.

Johs, B., Edwards, J. L., Shiralagi, K. T., Droopad, R., Choi, K. Y., Maracas, G. N., … Woollam, J. A. (1925). Real-time analysis of in-situ spectroscopic ellipsometric data during MBE growth of III-V semiconductors. In Nebraska Univ., Materials, Structures, and Devices for High-Speed Electronics.