Photoluminescence in CdTe grown on GaAs substrates by molecular beam epitaxy

Abstract

Single-crystal epitaxial layers of (100) and (111) oriented CdTe were grown on (100) oriented GaAs substrates by molecular beam epitaxy. Low-temperature (4.2 K) photoluminescence spectra exhibit free-exciton and bound-exciton peaks having linewidths on the order of 2 meV for both CdTe crystallographic orientations. However, defect-related photoluminescence is found to be stronger in (100) oriented CdTe.

Low temperature photoluminescence spectroscopy of thin film, polycrystalline CdTe/CdS solar cell structures

“…Because of this we cannot explicitly identify the impurities/defect centres involved. However, excitonic recombination involving halogen donors, including Cl, has been reported [16,34] at this energy. Exciton emission is not evident from CdTe/CdS interface excitation, which is consistent with previous work using CdTe/CdS interface excitation [24,25].…”

ZnSe/CdTe/ZnSe heterostructures

“…34,35 Moreover, no evidence of light-exciton recombination was observed at the highest excitation power densities explored in our samples. Such considerations suggest that the effect of the inhomogeneous residual strain within the CdTe layer-at most 0.24% along the ͓112͔ direction-on the heavy-hole, light-hole and conduction band edge is negligible.…”

Thick CZT detectors for spaceborne x-ray astronomy

“…53 Photoconductivity measurements can be used to measure the surface recombination rate. 54 These measurements can be combined with internal field mapping using the Pockels effect 55 and the response to alpha particles.…”

“…The technique is very sensitive to defect structure and impurities from the intrinsic material as well as from any subsequent surface preparation. 53 Photoconductivity measurements can be used to measure the surface recombination rate. 54 These measurements can be combined with internal field mapping using the Pockels effect 55 and the response to alpha particles.…”