Ultrawide Bandgap Laser Addressable Photoconductors

Executive Summary

We will develop, synthesize, and characterize custom, ultrawide-bandgap photoconducting materials for use in next-generation, high-power and high-speed devices. The new materials will enable increased fluence and repetition of high-energy laser systems, increased power density and frequencies in radio-frequency generation, and improved performance of power electronics in the electrical grid infrastructure.

Publications, Presentations, and Patents

Seyidov, Palvan, Joel B. Varley, Jimmy-Xuan Shen, Zbigniew Galazka, Ta-Shun Chou, Andreas Popp, Martin Albrecht, Klaus Irmscher, and Andreas Fiedler. 2023. "Charge State Transition Levels of Ni in β-Ga2O3 Crystals from Experiment and Theory: An Attractive Candidate for Compensation Doping." Journal of Applied Physics 134 (20): 205701. doi:10.1063/5.0173761 IM #1079535

Ghadi, Hemant, Joe F. McGlone, Evan Cornuelle, Alexander Senckowski, Shivam Sharma, Man Hoi Wong, Uttam Singisetti, et al. 2023. "Identification and Characterization of Deep Nitrogen Acceptors in β-Ga2O3 Using Defect Spectroscopies." APL Materials 11 (11): 111110. doi:10.1063/5.0160541 IM #1079537

Seyidov, Palvan, Joel B. Varley, Ymir Kalmann Frodason, Detlef Klimm, Lasse Vines, Zbigniew Galazka, Ta-Shun Chou, Andreas Popp, Klaus Irmscher, and Andreas Fiedler. 2023. "Thermal Stability of Schottky Contacts and Rearrangement of Defects in β-Ga2O3 Crystals." Advanced Electronic Materials. doi:10.1002/aelm.202300428 IM #1069346 

Frodason, Ymir K., Patryk P. Krzyzaniak, Lasse Vines, Joel B. Varley, Chris G. Van de Walle, and Klaus Magnus H. Johansen. 2023. "Diffusion of Sn Donors in β-Ga2O3." APL Materials 11 (4): 041121. doi:10.1063/5.0142671 IM #1069344

Frodason, Ymir K., Joel B. Varley, Klaus Magnus H. Johansen, Lasse Vines, and Chris G. Van de Walle. 2023. "Migration of Ga Vacancies and Interstitials in β-Ga2O3." Physical Review B 107 (2): 024109. doi:10.1103/physrevb.107.024109 IM #1065008 

Mukhopadhyay, Partha, Isa Hatipoglu, Ymir K. Frodason, Joel B. Varley, Martin S. Williams, Daniel A. Hunter, Naresh K. Gunasekar, et al. 2022. "Role of Defects in Ultra-High Gain in Fast Planar Tin Gallium Oxide UV-C Photodetector by MBE." Applied Physics Letters 121 (11): 111105. doi:10.1063/5.0107557 IM #1064852 

Lars Voss, "Understanding point defects and impurities in Ga203 and (AI,Ga)203 through atomistic simulations (IWG04)" (Invited presentation, 4th International Workshop on Gallium Oxide (IWGO4), Nagano, Japan Oct. 2022). IM #1063164

Lars Voss,"First-principles simulations of transition metal dopants and impurities in Ga2O3 and related alloys" (Invited Presentation, SPIE Photonics West Conference, San Francisco, CA, Feb. 2023). IM #1067897

Lars Voss, "Understanding the behavior of vacancies and complexes in Ga2O3 through atomistic simulations" (Invited Presentation, 32nd International Conference on Defects in Semiconductors, ICDS, Rehoboth Beach, DE, Sept. 2023). IM #1082826

Lars Voss, "Simulating Point Defects at Database Scale (ICDS)" (Presentation- Contributed, 32nd Conference on Defects in Semiconductors, Rehoboth Beach, DE, Sept. 2023). IM #1082915