Observation of electrically resettable negative persistent photoconductivity in InAs/AlSb single quantum wells
作者:
Fu‐Cheng Wang,
W. E. Zhang,
C. H. Yang,
M. J. Yang,
B. R. Bennett,
期刊:
Applied Physics Letters
(AIP Available online 1996)
卷期:
Volume 69,
issue 10
页码: 1417-1419
ISSN:0003-6951
年代: 1996
DOI:10.1063/1.117600
出版商: AIP
数据来源: AIP
摘要:
The mechanism of the negative persistent photoconductivity (NPPC) in InAs/AlSb single quantum wells is discussed. The molecular beam epitaxy grown single InAs quantum well sample is made into Hall bars with the substrate as the backgate. Using the newly designed buffer, the gate bias can deplete or enhance the two‐dimensional electrons in the InAs quantum well without substantial gate leakage current. Based on the 4.2 K magnetoresistance data, and the fact that the trapped electrons can be redistributed by gate bias, we conclude that the NPPC effect at low temperatures is a result of the capture of photoexcited electrons by ordinary, deep donors in AlSb. Numerical modeling using physical assumptions can quantitatively explain our experimental observation, and the calculated AlSb donor energy is 0.41±0.05 eV above the AlSb valence band maximum, with 4×1016/cm3to 1017/cm3in concentration. The previously discussedDX‐center‐like characteristic of deep levels in AlSb, i.e., lattice‐relaxation with a relatively high activation energy, is not evidenced in this work. ©1996 American Institute of Physics.
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