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Measurement of Local Electric Fields and the Onset of Breakdown in Ultra-wide Band Gap Semiconductor Devices using Photocurrent Spectroscopy

Abstract Details

2023, Doctor of Philosophy, Ohio State University, Materials Science and Engineering.
Ultra-wide-bandgap (UWBG) materials-based power electronic devices suffer from unexpected and uncertain locations of non-uniformity, and high fields degrade these devices, limiting their lifetimes. It is a challenge to identify the exact locations of breakdown (hot spots), and often destructive processes are used, which are costly, time- consuming, and often not realistic. The work presented here is an attempt to demonstrate a non-destructive and reliable photocurrent spectroscopy technique based on the exciton Franz-Keldysh effect in probing the local electric field (F). By including the excitonic effect in quantitatively modeling the absorption lineshape (and, in turn, photocurrent responsivity), F values are estimated while exploring a wide range of physics. A probe that measures F locally is an extremely useful tool for mapping out the F distribution, performing reliability testing, locating hot and cold spots, validating, or refining electrostatic models, and optimizing device geometry. Analyzing the F-dependent responsivity has shed insight into the contributions of self-trapped excitons and self- trapped holes in 𝛽 βˆ’ πΊπ‘Ž2𝑂3 to the photocurrent-production pathway. Polarization- dependent photocurrent spectroscopy is also performed to verify various excitonic transitions, identify the crystallographic axes, and understand their behavior with the applied bias. For solar-blind photodetectors, light polarization could help to make PDs more selective to deep UV wavelengths.
Roberto Myers (Advisor)
Andrea Serrani (Committee Member)
Tyler Grassman (Committee Member)
Wolfgang Windl (Committee Member)

Recommended Citations

Citations

  • Verma, D. (2023). Measurement of Local Electric Fields and the Onset of Breakdown in Ultra-wide Band Gap Semiconductor Devices using Photocurrent Spectroscopy [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1680187175688544

    APA Style (7th edition)

  • Verma, Darpan. Measurement of Local Electric Fields and the Onset of Breakdown in Ultra-wide Band Gap Semiconductor Devices using Photocurrent Spectroscopy. 2023. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1680187175688544.

    MLA Style (8th edition)

  • Verma, Darpan. "Measurement of Local Electric Fields and the Onset of Breakdown in Ultra-wide Band Gap Semiconductor Devices using Photocurrent Spectroscopy." Doctoral dissertation, Ohio State University, 2023. http://rave.ohiolink.edu/etdc/view?acc_num=osu1680187175688544

    Chicago Manual of Style (17th edition)