Faculty Profile for Dr. Edwin L Piner

profile photo for Dr. Edwin L Piner
Dr. Edwin L Piner
Professor — Physics
RFM 3208
phone: (512) 245-7049

Biography Section

Biography and Education

Prof. Piner’s research and technology development interests are in the growth and characterization, semiconductor fabrication, and performance optimization of gallium nitride, aluminum nitride and their alloys for device applications. Less than one-tenth of the lab performance capability of III-Nitride electronic devices has been realized commercially. Thermal impedance is a key hindrance to closing this gap. The nitrogen-face of the polar GaN crystal is a noteworthy research field. Coupled with chemical vapor deposition diamond, N-face GaN FETs will offer the next device performance revolution of Wide Bandgap Semiconductors (WBGs) in a variety of harsh environments, including high temperature applications. The AlGaN/GaN structure has particularly sensitive surface states coupled to the 2DEG channel of the FET. The sensitivity is exploitable for biological, radiological, chemical, and environmental sensors.

Prof. Piner's Texas State team has demonstrated a technique to grow single crystal GaN on patterned diamond. The technique involves epitaxial lateral overgrowth of III-Nitride thin film on exposed diamond windows demonstrating, for the first time, direct contact between III-Nitride semiconductors and diamond, without intervening passivating or protection layers. Combining this new technique with Ultra Wideband Gap (UWBG) semiconductors and heterojunctions will enable better modeling to comprehend phonon and vibrational-modes in UWBG materials and their interfaces with diamond, as well as lead to the interesting p-diamond/n-Al(Ga)N junction to study electrical transport and the potential for such a p-n junction for device applications. UWBG hetero-integration with diamond is expected to revolutionize the thermal transport challenges of high Al-content AlGaN/AlN (and gallium oxide, in the future) as well as enable a novel electrical junction device.

The combinable features of III-Nitride materials; N-face surface, wireless functionality, and harsh environment immunity in a single, environmentally safe, semiconductor material system, could pioneer a new era in solid-state device utilization for extreme applications.

Research Interests

Dr. Piner's group is principally focused on research and technology development in the growth and characterization, semiconductor fabrication, and performance optimization of wide & ultrawide bandgap materials for solid-state device applications.

Selected Scholarly/Creative Work

  • Siddique, A., Ahmed, R., Anderson, J. W., Holtz, M. W., & Piner, E. L. (2021). Improved Electrical Properties of AlGaN/GaN High-Electron-Mobility Transistors by In Situ Tailoring the SiNx Passivation Layer. ACS Applied Materials \& Interfaces, 13, 18264–18273. https://doi.org/10.1021/acsami.1c01241
  • Ahmed, R., Siddique, A., Anderson, J. W., Gautam, C., Holtz, M. W., & Piner, E. L. (2020). Integration of GaN and Diamond Using Epitaxial Lateral Overgrowth. ACS Applied Materials \& Interfaces, 12(35), 39397–39404. https://doi.org/10.1021/acsami.0c10065
  • Ahmed, R., Siddique, A., Saha, R., Anderson, J. W., Engdahl, C., Holtz, M. W., & Piner, E. L. (2020). Effect of precursor stoichiometry on morphology, phase purity, and texture formation of hot filament CVD diamond films grown on Si (100) substrate. Journal of Materials Science: Materials in Electronics, 31, 8597–8606. https://doi.org/10.1007/s10854-020-03395-7
  • Yates, L., Anderson, J., Gu, X., Lee, C., Bai, T., Mecklenburg, M., … Graham, S. (2018). Low Thermal Boundary Resistance Interfaces for GaN-on-Diamond Devices. ACS Appl. Mater. Interfaces, 10(28), 24302–24309. https://doi.org/10.1021/acsami.8b07014
  • Ahmed, R., Nazari, M., Hancock, B. L., Simpson, J., Engdahl, C., Piner, E. L., & Holtz, M. W. (2018). Ultraviolet micro-Raman stress map of polycrystalline diamond grown selectively on silicon substrates using chemical vapor deposition. Applied Physics Letters, 112(18), 181907. https://doi.org/10.1063/1.5027507

Selected Awards

  • Award / Honor Recipient: Presidential Distinction Award for Excellence in Scholarly / Creative Activities, College of Science and Engineering, Physics. 2014
  • Award / Honor Recipient: The Graduate College’s Outstanding Master’s Thesis Award in Math, Physical Sciences and Engineering, Texas State University. 2014
  • Award / Honor Recipient: Best Paper Award, "New Technologies for Improving the High Frequency Performance of AlGaN/GaN High Electron Mobility Transistors", International Conf. on Advances in Electronics and Microelectronics, 2008, ENICS, Valencia, Spain, EU. September 1, 2008 - October 1, 2008
  • Award / Honor Recipient: Engineers Council, NCSU Student Government. January 1, 1993
  • Award / Honor Recipient: Alpha Sigma Mu, Honorary Engineering Fraternity. January 1, 1900

Selected Grants

  • Holtz, Mark W (Principal), Chen, Yihong (Supporting), Geerts, Wilhelmus J (Supporting), Droopad, Ravindranath (Supporting), Li, Jian (Co-Principal), Myers, Thomas H (Supporting), Piner, Edwin L (Supporting), Theodoropoulou, Nikoleta (Supporting), Zakhidov, Alexander (Supporting). System of Integrated Characterization of Electronic Devices and Materials, U.S. AFOSR, Federal, $332086. (Funded: August 15, 2017 - August 14, 2018). Grant.
  • Piner, Edwin L (Principal), Holtz, Mark W (Co-Principal). Integrated GaN HEMT on Diamond: Heterointerface and Thermal Transport Fundamentals, U. S. Army, Federal, $596000. (Funded: 2014 - 2017). Grant.
  • Piner, Edwin L (Principal), Holtz, Mark W (Co-Principal). Heterogeneous Integration of Diamond and Ultrawide-Bandgap Semiconductors for Fundamental Phonon and Electron Transport Studies, U.S. Army, Federal, $660000. (Funded: July 2020 - June 2023). Grant.
  • Piner, Edwin L (Principal), Scolfaro, Luisa M (Co-Principal). Improving Thermal Management in GaN HEMTs via Simulation of TDTR Characterization, Research Enhancement Program, Texas State University, $16000. (Funded: January 2020 - May 2021). Grant.
  • Piner, Edwin L (Principal), Holtz, Mark W (Co-Principal). Integrated Selective Growth of Diamond and GaN for Thermal Management, NSF-EPMD, Federal, $410000. (Funded: July 1, 2018 - June 30, 2021). Grant.

Selected Service Activities

STEM Workforce Advisory Council
January 2022-Present
Materials with Intelligence
August 2019-Present
CIEDAR Working Group
July 2019-Present
Curriculum Committee
June 2017-Present
Physics Graduate Advisor
January 2017-Present