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Excitation and recombination of donor–acceptor pairs in ZnTe
Author(s) -
Nakashima S.,
Yasuda S.
Publication year - 1979
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.2220960120
Subject(s) - excited state , atomic physics , excitation , acceptor , electron , photoluminescence , recombination , free electron model , spectral line , bound state , ground state , redistribution (election) , relaxation (psychology) , impurity , chemistry , molecular physics , materials science , physics , condensed matter physics , psychology , social psychology , biochemistry , optoelectronics , organic chemistry , quantum mechanics , astronomy , politics , political science , law , gene
The photoluminescence spectra and its excitation spectra of the donor‐acceptor pairs are observed in ZnTe crystals doped with Li and As in the region below the bandgap energy. The relaxation of electrons and holes into the first excited state of d‐a paris is studied for the three excitation processes: (1) bound‐to‐bound transitions, (2) bound‐to‐free transitions, and (3) free‐to‐free transitions. It is concluded that most of the electrons and holes at the excited states of each impurity level are relaxed rapidly into their ground states before the occurrence of the recombination involving the excited states. For the excitation process (2), conduction electrons are preferentially trapped by positively charged pairs. The redistribution of bound holes by hopping is suggested to explain the broad d– a emission band observed for the bound‐to‐free excitation for very distant pairs.