H. Kudo et al., Temperature-independent stokes shift in an In0.08Ga0.92N epitaxial layer revealed by photoluminescence excitation spectroscopy, PHYS ST S-B, 228(1), 2001, pp. 55-58
Optical properties of an In0.08Ga0.92N epitaxial laver have been studied by
means of photoluminescence excitation spectroscopy. The photoluminescence
spectrum of the In0.08Ga0.92N epitaxial layer was composed of two emission
components with an energy separation of 40 meV, Photoluminescence excitatio
n measurements allowed us to observe a clear peak due to the absorption of
InGaN and to investigate the temperature dependence of the Stokes shift. At
100 K, the Stokes shifts of the higher and lower energy components were es
timated to be 44 and 79 meV. respectively. The Stokes shifts were well cons
istent with the energy shifts expected from the polaron interaction. The ab
sorption peaks for both the higher and lower energy components were located
at the same energy position. Furthermore, the Stokes shift of the higher e
nergy component was not dependent on temperature and indicated a constant v
alue up to room temperature.