ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Sputter-deposited, heteroepitaxial (100)CdTe layers prepared at growth temperatures of 300–325 °C are found to be p-type with high dark resistivities on the order of 2×105 Ω cm. The epilayers are highly photoconducting and exhibit photoconductivity to dark conductivity ratios as high as 1×106 at around 200 K. The photoconductivity is observed to exhibit a sublinear dependence on illumination intensity and a thermally activated behavior. The model developed by Simmons and Taylor [J. G. Simmons and G. W. Taylor, J. Phys. C: Solid State Phys. 7, 3051 (1974); G. W. Taylor and J. G. Simmons, J. Phys. C: Solid State Phys. 7, 3067 (1974)] to explain photoconductivity in amorphous semiconductors is shown to be applicable to these epitaxial layers. Hole traps at 0.40 and 0.23 eV above the valence band have been determined from the temperature dependence of the photoconductivity. Acceptor levels at 0.62 and 0.07 eV above the valence band, determined from the temperature dependence of the dark conductivity, are discussed in relation with photoluminescence bands at 0.81 and 1.00 eV reported earlier [S. R. Das, J. G. Cook, N. L. Rowell, and M. S. Aouadi, J. Appl. Phys. 68, 5796 (1990)] in these epilayers.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.347424
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