CuIn(SxSe1-x)(2) films prepared by graphite box annealing of In/Cu stackedelemental layers

CuIn(SxSe1-x)(2) films were synthesized by sulphurization of In/Cu stacked elemental layers deposited onto glass and Mo-coated glass substrates follow ed by selenization by graphite box annealing. The films, thus synthesized, were characterized by measuring electrical, optical and microstructural pro perties. The microstructure and hence the physical properties of the films depended critically on the amount of sulphur incorporation. Nature of charg e carriers depended on Cu/In, (S + Se)/(Cu + In) and S/(S + Se) ratios whil e their concentrations varied between 10(16) and 10(19) cm(-3). Grain bound ary scattering effects were critically studied by measuring the electrical conductivity (sigma) and Hall mobility (mu) simultaneously on the same samp le. Optical transmittance studies indicated the band gap to vary within 0.9 8-1.40eV with x values. The photoluminescence spectra, recorded at 80 K wer e dominated by the excitonic peak located within 1.40-1.6eV followed by a s mall peak within similar to 0.96-0.98 eV arising due to transition from con duction band to neutral acceptor (V-Cu) or exciton bound to ionized accepto r (Cu-In) states. (C) 2001 Elsevier Science Ltd. All rights reserved.