Electroreflection |
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The electroreflectance (ER) spectra of semiconductors in
a strong electric field should contain an oscillating part
connected, in according with the Franz-Keldysh theory, with the modulation
of the reduced density of states beyond the absorption edge. These
oscillations are the result of interference between the wave functions of
the electron and holes, which appear in interband optical transitions. We
managed to reach a high degree of homogeneity of the electrical field at a
depth at which the reflected light wave with the help of the recording the
ER spectra under conditions nonequilibrium depletion in the space charge
region in high-resistance germanium samples [IG Neizvestny, NN Ovsyuk, and MP Sinyukov. JETP
Letters 24, 359 (1976)]. We have shown that the study
of multioscillatory ER spectra is a new, efficient method for
investigating mechanisms of scattering of charge carriers. The high
sensitivity of this method has made it possible to determine for the first
time the magnitude of anisotropy of the optical deformation potentials of
holes [NN Ovsyuk. JETP Letters 38, 149 (1983)]. Singularities associated with the effect of size
quantization on interband optical transitions in the region of the space
charge of a semiconductor were observed for the first time in the
electroreflectance spectra of the semiconductors [NN Ovsyuk and MP Sinyukov. JETP Letters 32, 342 (1980)]. We have proposed the independent method of
determining the Luttinger band parameters of a semiconductor, which
determine the dispersion law E(k) [OA Makarov, NN Ovsyuk, and MP Sinyukov. JETP 57, 1318 (1983)].
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