Premium
Temporally and Spatially Resolved Spectroscopy of GaN
Author(s) -
Korona K. P.,
Kuhl J.,
Baranowski J. M.
Publication year - 1999
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(199909)215:1<53::aid-pssb53>3.0.co;2-6
Subject(s) - exciton , photoluminescence , metalorganic vapour phase epitaxy , spectroscopy , excitation , chemical vapor deposition , materials science , diffusion , molecular physics , liquid helium , atomic physics , helium , optoelectronics , condensed matter physics , chemistry , physics , nanotechnology , epitaxy , layer (electronics) , quantum mechanics , thermodynamics
We report temporally and spatially resolved photoluminescence (PL) measurements on a high‐quality single crystal GaN film grown on GaN substrates by metalorganic chemical vapour deposition (MOCVD). The PL decay times for the free A‐excitons and the donor‐bound excitons obtained under low excitation density (100 W/cm 2 ) at liquid helium temperature were about 60 and 250 ps, respectively. Measurements of the PL under higher excitation densities (up to 9 kW/cm 2 ) show that the recombination rates of both free and bound excitons are slower, this observation can be explained by detrapping of donor bound excitons. In spatially resolved measurements, a slight time delay of the free exciton photoluminescence for distant points has been observed. Numerical modeling shows that this delay can be explained by an exciton‐polariton transport with a diffusion constant of approximately 100 cm 2 /s.