CdCl2 activation annealing of CdTe microwires grown by close-spaced sublimation method

Abstract

We report on the effect of CdCl2 treatment on CdTe microwires that were grown using a simple close-spaced sublimation method. Au particles were used for catalytic vapor-liquid-solid growth of the CdTe microwires with a direct band-gap of ~1.49 eV. The optical, morphological and structural properties of the CdTe microwires were characterized after post-growth CdCl 2 treatment at 385°C for 15 ~ 90 min by scanning electron microscopy, X-ray diffraction, μ-Raman scattering, μ-photoluminescence spectroscopy and focused-ion-beam techniques. New grains nucleated at the surface of CdTe microwires were observed after CdCl2 treatment. The orientations of the CdTe microwires and of the underlying CdTe thin films became more randomized with increasing durations of CdCl2 treatment. However, the optical properties were hardly affected by CdCl2 treatment. Post-growth CdCl2 activation on CdTe microwires is a critical process for high efficiency CdTe microwire-based solar cells. © 2014 The Electrochemical Society.