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Optical Properties and Switching Behaviour of Excited III–V Semiconductors near the Direct–Indirect Cross‐Over
Author(s) -
Gürtler S.,
Schwabe R.,
Staehli J. L.,
Unger K.
Publication year - 1992
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.2221730144
Subject(s) - excited state , semiconductor , photoluminescence , excitation , electron , condensed matter physics , conduction band , chemistry , atomic physics , materials science , physics , optoelectronics , quantum mechanics
In highly excited semiconductor systems near the transition from direct to indirect band structure (cross‐over) the energetic distance between different conduction band minima is a nonmonotonous function of the excitation intensity. A theoretical explanation of this experimental result is given. Our investigations are based on the evaluation of photoluminescence spectra using a careful lineshape analysis. The nonmonotony is a consequence of the unequal shrinkage of the direct and indirect gaps as a function of the population of energetically comparable conduction band valleys in a material near cross‐over. In the situation discussed an optical switching mechanism is expected, which is explained with special respect to its switching time. Important problems of electron–electron interaction are discussed.