Original scientific paper
The Einstein relation in superlattices of non-parabolic semiconductors with graded interfaces under magnetic quantization
Kamakhya Prasad Ghatak
; Department of Electronic Science, University of Calcutta, University College of Science and Technology, 92, Acharya Prafulla Chandra Road, Calcutta - 700 009, India
Sambhu N. Banik
; Department of Physics, Dandirhat Nagendrakumar Uchcha Siksha Niketan, P. O. Dandirhat, Dt. North 24 Parganas, West Bengal, India
Abstract
We study the Einstein relation under magnetic quantization in III-V, II-VI, PbSnTe/PbTe, strained layer and HgTe/CdTe superlattices with graded interfaces and compare the same with that of the corresponding bulk specimens of the constituent materials. It is found, taking GaAs/Ga1-xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaSb and HgTe/CdTe superlattices with graded interfaces as examples, that the Einstein relation exhibits oscillatory dependence with the inverse quantizing magnetic field due to the Shubnikov-de Haas effect, and increases with increasing electron concentration in an oscillatory manner in all the cases. The ratio of diffusivity to mobility in graded superlattices is greater than that of constituent bulk materials. The oscillations in HgTe/CdTe superlattices show up much more significantly as compared to other systems. In addition, we have suggested an experimental method of determining the Einstein relation in degenerate materials having arbitrary dispersion laws.
Keywords
Hrčak ID:
299433
URI
Publication date:
1.9.1994.
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