“Fundamentals of Doping and Defects in Ga₂O₃ for High Breakdown Field Electronics”

Funding: Department of Defense Multidisciplinary University Research Initiative (MURI)

Partners:  University of Utah, Pennsylvania State University, University of Illinois-Urbana Champaign

IMR’s ultrawide bandgap research focuses on Gallium Oxide (Ga₂O₃), a promising material for high voltage breakdown devices and deep UV LEDs. Crystals of Ga₂O₃ are grown on-site with a Czochralski furnace at temperatures exceeding 1800C and later characterized with the purpose of studying optical, electronic, and defect properties. Measurement techniques include UV-vis-NIR, Hall Effect, XRD, DLTS, TEES and PAS. Doping of Ga₂O₃ crystals has been studied, with the intention of increasing material conductivity and improving crystallinity and Czochralski growth methods. Researchers at WSU work together with collaborators at The University of Utah in a tightly organized team to improve Ga₂O₃ device performance from a synthesis standpoint.

Publications 2021:

1. Jani Jesenovec, Cassandra Remple, Jesse Huso, Benjamin Dutton, Parker Toews, Matthew D. McCluskey, John S. McCloy, “Photodarkening and Dopant Segregation in Cu-doped b-Ga₂O₃ Czochralski Single Crystals,” Journal of Crystal Growth, 578, 126419 (2022). https://doi.org/10.1016/j.jcrysgro.2021.126419
2. Adrian Chmielewski, Ziling Deng, Muad Saleh, Jani Jesenovec, Wolfgang Windl, Kelvin Lynn, John McCloy, Nasim Alem, “Atomic-Scale Characterization of Structural and Electronic Properties of Hf doped β-Ga₂O₃” Applied Physics Letters, 119, 172102 (2021). https://doi.org/10.1063/5.0062739
3. Christopher Pansegrau, Jani Jesenovec, John McCloy, Matthew McCluskey, “Zinc-hydrogen and zinc-iridium pairs in β-Ga₂O₃,” Applied Physics Letters, 119(10), 102104 (2021), http://doi.org/10.1063/5.0062059
4. Jani Jesenovec, Marc Weber, Christopher Pansegrau, Matthew McCluskey, Kelvin Lynn, and John McCloy, “Gallium Vacancy Formation in Oxygen Annealed β-Ga₂O₃,” Journal of Applied Physics, 129(24), 245701 (2021). https://doi.org/10.1063/5.0053325
5. J. Jesenovec, J. Varley, S.E. Karcher, and J.S. McCloy, “Electronic and optical properties of Zn-doped β-Ga₂O₃ Czochralski single crystals,” Journal of Applied Physics, 129(22), 225702 (2021). https://doi.org/10.1063/5.0050468
6. Santosh Swain, Marc Weber, Jani Jesenovec, Muad Saleh, Kelvin Lynn, John McCloy, “Compensation by gallium vacancies and iron acceptors in β-Ga₂O₃,” Physical Review Applied, 15(5), 054010 (2021). https://doi.org/10.1103/PhysRevApplied.15.054010
7. Timothy Gustafson, Jani Jesenovec, Christopher Lenyk, Nancy Giles, John McCloy, Matthew McCluskey, and Larry Halliburton, “Zn acceptors in β-Ga₂O₃ crystals,” Journal of Applied Physics, 129(15), 155701 (2021). https://doi.org/10.1063/5.0047947

Selected Publications 2018-2020:

• Ritter, J.R., J. Huso, P.T. Dickens, J.B. Varley, K.G. Lynn, and M.D. McCluskey, “Compensation and hydrogen passivation of magnesium acceptors in β-Ga₂O₃,” Applied Physics Letters, 113(5), 052101 (2018).
• Wang, Y., P.T. Dickens, J.B. Varley, X. Ni, E. Lotubai, S. Sprawls, F. Liu, V. Lordi, S. Krishnamoorthy, S. Blair, K.G. Lynn, M. Scarpulla, and B. Sensale-Rodriguez, “Incident wavelength and polarization dependence of spectral shifts in β-Ga₂O₃ UV photoluminescence,” Scientific Reports, 8(1), 18075 (2018).
• Saleh, M., J.B. Varley, J. Jesenovec, A. Bhattacharyya, S. Krishnamoorthy, S. Swain, and K. Lynn, “Degenerate doping in β-Ga₂O₃ single crystals through Hf-doping,” Semiconductor Science and Technology, 35(4), 04LT01 (2020).
• Saleh, M., A. Bhattacharyya, J.B. Varley, S. Swain, J. Jesenovec, S. Krishnamoorthy, and K. Lynn, “Electrical and optical properties of Zr doped β-Ga₂O₃ single crystals,” Applied Physics Express, 12(8), 085502 (2019).
• Compound Semiconductor Article: Zirconium Doping Improves Gallium Oxide