Spray pyrolysis deposition of p-CdTe films: Structural, optical and electrical properties

The present communication reports the structural, optical and electrical properties of p-CdTe films deposited by using spray pyrolysis technique on thoroughly cleaned sodalime glass substrates at 350 degrees C in inert N-2 atmosphere. The films were characterized by using XRD, Raman spectroscopy, XPS, thickness profiler, SEM, EDAX and UV-Visible spectroscopy and Hall parameters measurement. The structural studies showed the formation of pure cubic CdTe in resultant films with crystallite size = 32 nm. The texture coefficient TC(hkl) indicated preferential orientation of films along [311] and [511] directions. The SEM image showed almost spherical granules with average size of 0.25 mu m. From UV-Visible spectral data, the maximum absorbance and direct band gap obtained using Tauc plot are found to be 0.94 and E-g= 1.44 eV respectively for films having thickness, t = 3.2 mu m. The Hot probe experiment, Hall coefficient R-H = 1.478 x 10(3) cm(3)/C, and resistivity rho = 2.228 x 10(1) Omega cm confirmed the p-type semiconducting behavior of CdTe films. The mobility of majority charge carriers - holes is found to be mu = 6.63 x 10(1) cm(2)/Vs. The films processed using present work can be treated as possible p-type candidate for fabrication of hetero-junction solar cell. (C) 2013 Elsevier Ltd. All rights reserved.