Cryst. Res. Technol. 37 2002 4 329–339 © WILEY-VCH Verlag Berlin GmbH, 13086 Berlin, 2002 0232-1300/02/0404-0329 $ 17.50+.50/0 T. MAHALINGAM* ,1 , V. S. JOHN 1,3 , G. RAVI 1 , P. J. SEBASTIAN 2 1 Department of Physics, Alagappa University, Karaikudi– 630 003, Tamil Nadu, India 2 Solar–Hydrogen–Fuel Cell Group, Energy Research Centre, Unam – 62580, Morelos 3 Department of Physics, T.D.M.N.S. College, T. Kallikulam– 627 113, Tamil Nadu, India Microstructural Characterization of Electrosynthesized ZnTe Thin Films Thin films of zinc telluride (ZnTe) were electrosynthesized on tin oxide coated conducting glass substrates at various bath temperatures. The deposited films were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The structure was found to be cubic with preferential orientation along (111) plane. X-ray line profile analysis technique by the method of the variance has been used to evaluate the microstructural parameters. The variation of different microstructural parameters such as, crystallite size, RMS strain, dislocation density and stacking fault probability affecting the fraction of planes with film thickness and bath temperatures were studied. The experimental observations are discussed in detail. Keywords: zinc telluride, electrosynthesis, line broadening, microstructural parameters, surface morphology (Received October 12, 2001; Accepted February 5, 2002) 1. Introduction In recent years, there has been a growing interest in the study of zinc telluride (ZnTe) thin films, as it is a potentially low-cost semiconductor for switching devices and multi-junction solar cells. ZnTe, being a wide and direct band gap (2.26 eV) semiconducting material (NISHIO;HAYSHIDA et al.) with low electronic affinity (3.53 eV) (KASHYOUT;ARICO et al.), it can absorb photons in the visible region without any phonon assisted mechanism that makes it useful in several electro-optic and opto-electronic applications. Recent advancements in thin film solar cell technology have indicated that ZnTe and its alloys may effectively been used in CdTe based solar cells (ZENIA;LEVY-CLEMENT et al.). The parameters affecting the cell performance in CdTe were tackled by the Ametek group using n-i-p structures (MAYERS) with a thin layer of intrinsic CdTe and a p-type ZnTe layer. Polycrystalline ZnTe films and its alloys like CdZnTe were successfully utilized in the fabrication of tandem solar cell structures with a tailored band gap (ROHATGI; SUDHARSANAN et al.) and quantum well structures (KALITA;SARMA et al.). ZnTe was also proposed as passivation layer for HgCdTe surfaces in MIS devices (KÖNIGSTEIN and NEUMANN-SPALLART). All these created a renewed interest in the studies of ZnTe films for device applications. A variety of preparation techniques have been reported so far to obtain device-grade films. Some of them are: thermal evaporation (AQILI;ALI et al.), vapour phase epitaxy (KHAN), molecular beam epitaxy (TAO;TURKOVIC et al.), hot wall epitaxy (MERCHANT; COCIVERA et al.), metallorganic vapour phase epitaxy (WOLF;STANZL et al.), r.f. sputtering * corresponding author: maha51@lycos.com