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Pseudo‐Exciton Effect in the Schottky‐Barrier Electroreflectance
Author(s) -
Kiselev V. A.
Publication year - 1982
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221110206
Subject(s) - exciton , condensed matter physics , reflection (computer programming) , schottky barrier , semiconductor , spectral line , chemistry , electric field , biexciton , space charge , rotation (mathematics) , line (geometry) , materials science , physics , optoelectronics , quantum mechanics , electron , geometry , mathematics , diode , computer science , programming language
Abstract An account of the nonhomogeneity of the electric field in the space‐charge region of a semiconductor is presented. It is shown that the nonuniform field can lead to a sharp feature in the reflection spectra in the vicinity of a direct gap. The behaviour of this new lineshape with varying surface potential reproduces closely the behaviour of the exciton lineshape in reflection for which the phenomenon of “rotation” is well known. This effect is determined by the nonuniform character of the joint density of states involved in the band‐to‐band transition in the direction normal to the surface. The modulated electroreflectance spectra obtained employing the theory that neglects exciton effects are in good agreement with literature results of measurements on GaAs with donor concentration of 4.5 × 10 16 cm −3 at room temperature. A possible application of the observed phenomenon, as well as that of the exciton lineshape rotation, to investigate the energy and time characteristics of the space‐charge region and surface (interface) states is discussed.