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The “Quasidirect” Radiative Recombination of Free Holes at Neutral Shallow Donors in GaP
Author(s) -
Bindemann R.,
Schwabe R.,
Hänsel T.
Publication year - 1978
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.2220870120
Subject(s) - excitation , atomic physics , luminescence , exciton , band gap , phonon , shallow donor , line (geometry) , free electron model , acceptor , radiative transfer , range (aeronautics) , recombination , electron , physics , condensed matter physics , chemistry , doping , materials science , optics , quantum mechanics , biochemistry , geometry , mathematics , composite material , gene
The luminescence band at 2.24 eV in n‐type GaP is investigated in the temperature range of T = 27 to 120 K. It consists of a no‐phonon line and several phonon replicas (TA X , LA X , TO X ), which overlap with the donor–acceptor pair band. According to the analysis of the line shape and the energetic position of the intensity maximum in dependence of the temperature, the excitation intensity, and the time after excitation this band can be interpreted as being caused by free (hole)‐to‐bound (electron bound at the sulfur donor) transition. Taking into account the consequences of the GaP band structure on the symmetry properties of the bound electron states the free‐to‐bound transition is described as ‘quasidirect’. The calculated line shape is in good agreement with experiment using an indirect gap value which is 11 meV higher than accepted hitherto. The obtained indirect gap energy and free exciton binding energy are determined to E g ( T = 4.2 K) = (2.350 ± 0.002) eV and E FE = (22 ± 2) meV, respectively.