Al-doped ZnS layers synthesized by solution growth method

ZnS is one of the potential candidates as a window/buffer layer for solar photovoltaic applications. Al-doped ZnS nanocrystalline films were grown by a simple and economic process, chemical solution growth method. The layers were prepared for different Al-dopant concentrations that vary in the range, 0 -10 at. %. The effect of Al-doping on the composition, structure, optical, electrical and photo-luminescence properties of the synthesized layers was determined using appropriate techniques. The elemental composition of a typical sample with 6 at. % 'Al' in ZnS was Zn = 44.9 at. %, S = 49.8 at. % and Al = 5.3 at. %. The films were nanocrystalline in nature and showed (111) plane of ZnS as the preferred orientation for all the doping concentrations. The layers with 6 at. % of Al showed a crystallite size of similar to 9 nm. The FTIR studies confirmed the presence of ZnS in the layers. The layers showed an average transmittance of similar to 75% in the visible region. The change of photoluminescence behaviour with dopant concentration was also studied. The electrical resistivity was considerably decreased from 10(7) Omega cm to 10(3) Omega cm with Al-doping. The detailed analysis of results will be presented and discussed. (C) 2011 Elsevier B. V. All rights reserved.