Photoluminescence studies of CdTe polycrystalline films

Abstract

Photoluminescence (PL) studies of CdTe polycrystalline films are reported. The films were grown using the modified close space sublimation technique on sapphire substrates. The mean grain size in the investigated films was ranged from 10 up to 360 μm. The distinct spectral bands around 1.580 and 1.440 eV were observed at 77 K. These bands are attributed to shallow bound excitons at dislocations and deep defects, respectively. The intensity of luminescence related to dislocation defects is found to be proportional to the density of grain boundaries. The nature of grain boundaries in the investigated films has been briefly discussed.

Characterization of grain boundaries in CdTe polycrystalline films

“…In the above estimation, the spatial distribution of defects is assumed to be uniform. However, it has been previously shown that in the investigated films the grain boundaries are represented by the dislocation network [23]. Taking into account the gettering effect of dislocations in polycrystalline films [24], this result implies inhomogeneous distribution of impurities in the intragrain regions.…”

Theoretical calculation of cathodoluminescence: Influence of surface and bulk parameters on the depletion region of p-type CdTe

“…7,8 The direct gap of this material allows the generation of a significant cathodoluminescence signal CL, which facilitates its theoretical study in terms of some important parameters influencing several industrial applications. The different results are obtained using the generation function of Wu and Wittry 9 adjusted to CdTe.…”