T. Ganguli et A. Ingale, Raman and photoluminescence investigations of disorder in ZnSe films deposited on n-GaAs, PHYS REV B, 60(16), 1999, pp. 11618-11623
We report Raman and photoluminescence studies of ZnSe films deposited on a
(100) n-GaAs substrate by pulsed laser deposition. We have investigated the
disorder in the thin films of ZnSe by analyzing the asymmetry of the ZnSe
LO modes. We find that the best fit of the line shape is obtained using the
spatial correlation model and invoking the presence of a zone edge LO phon
on. This zone edge LO phonon is attributed to the presence of disorder in t
he material. The intensity of this disorder activated zone edge phonon is f
ound to correlate very well with the results of the crystal quality obtaine
d from x-ray diffraction. In addition we have studied the variation of the
depletion widths in the GaAs substrate as a function of the deposition para
meters of ZnSe, using the intensity ratios of the LO and L_ modes of an n-G
aAs substrate. We have also analyzed the origin of the deep center luminesc
ence observed in these films. The information is found to be complementary
and consistent with that obtained by Raman spectroscopy and the variations
expected due to different deposition conditions. [S0163-1829(99)13439-8].