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Growth optimization for low residual carriers in undoped midinfrared InAs/GaSb superlattices.
- Source :
-
Journal of Applied Physics . Oct2008, Vol. 104 Issue 7, p073111. 4p. 1 Chart, 4 Graphs. - Publication Year :
- 2008
-
Abstract
- Reducing residual background carriers in InAs/GaSb superlattices (SLs) is an essential task to increase the operating temperature of photoconductive devices. This paper discusses how low-temperature Hall measurements were used to tune several SL growth parameters for the minimum residual carriers in a typical midinfrared 21 Å InAs/24 Å GaSb SLs designed for the 4 μm cutoff wavelength. Among the three growth parameters studied, neither growth temperature nor in situ postannealing significantly affected the intrinsic carrier type and doping concentration. The lowest carrier density of 1.8×1011 cm-2 was achieved at 400 °C. All SLs grown at 400 °C maintained the lowest density around 1.6×1011 cm-2 with or without postannealing. However, in-plane carrier mobility showed a slight improvement with annealing, especially at temperatures above 450 °C. The growth parameter most sensitive to the carrier density was interface control. With a minor variation in interface shutter sequence, the carrier density dramatically increased from ∼2×1011 to 5×1012 cm-2, and the corresponding mobility dropped from 6600 to 26 cm2/V s, indicating dramatic degradation of interfacial quality. All SLs investigated in this study were residually p-type. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 104
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 34829112
- Full Text :
- https://doi.org/10.1063/1.2993748