Persistent photoconductivity in a two-dimensional electron gas system formed by an AlGaN/GaN heterostructure
- Department of Physics, Kansas State University, Manhattan, Kansas 66506-2601 (United States)
- APA Optics, Incorporated, 2950 North East 84th Lane, Blaine, Minnesota 55449 (United States)
Persistent photoconductivity (PPC) effect associated with a two-dimensional electron gas (2DEG) in an AlGaN/GaN heterojunction device has been observed. As a consequence, the device was observed to be sensitive to light and the sensitivity was associated with a permanent photoinduced increase in the 2DEG carrier mobility and density. By formulating the PPC buildup and decay kinetics, we attributed the observed increase in the 2DEG carrier density and mobility to the photoionization of deep level impurities (DX like centers) in the AlGaN barrier material. In the PPC state, we were able to continuously vary the 2DEG carrier density in a single sample through photoexcitation and it has been found that the 2DEG carrier mobility increases almost linearly with the carrier density in the 2DEG channel. At 10 K, an electron mobility of 5800cm{sup 2}/V{center_dot}s has been obtained in a PPC state. Implications of these observations on the device applications based on AlGaN/GaN heterojunctions have also been discussed. {copyright} {ital 1997 American Institute of Physics.}
- DOE Contract Number:
- FG03-96ER45604
- OSTI ID:
- 656105
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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