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Photoluminescence and Absorption Edge of Undoped and Doped GaN Films
Author(s) -
Jacobson M.A.,
Nelson D.K.,
Romanovsky S.O.
Publication year - 1998
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/(sici)1521-3951(199812)210:2<475::aid-pssb475>3.0.co;2-d
Subject(s) - photoluminescence , doping , materials science , exciton , absorption edge , optoelectronics , absorption (acoustics) , impurity , epitaxy , spectral line , absorption spectroscopy , condensed matter physics , optics , band gap , chemistry , nanotechnology , physics , layer (electronics) , composite material , organic chemistry , astronomy
Photoluminescence and absorption spectra of undoped and Si‐doped GaN films have been studied. It was shown that moderate Si doping improves the optical properties of GaN epitaxial layers. The further increase of doping concentration results in a red shift and broadening of bound exciton line. The broadening seems to be due to potential fluctuations caused by randomly distributed donor impurities. The analysis of temperature dependence of GaN photoluminescence spectra allowed us to reveal the E 1 2 optical‐phonon replica of free exciton. The observed flattening of absorption edge with doping can be described in terms of Urbach rule.