Pulsed laser deposition of Cu2ZnSn(SxSe1-x )4 thin film solar cells using quaternary oxide target prepared by combustion method

Cu2ZnSn(SxSe1-x)(4) thin film solar cells have been fabricated by pulsed laser deposition using single quaternary oxide target prepared by combustion method. Compared with the traditional ball milling process, the innovative application of combustion method on preparing PLD target greatly ensures the homogeneous distribution of chemical compositions in the deposited film. The improved selenization after sulfurization (SAS) method is successfully employed to synthesize Cu2ZnSn(SxSe1-x)(4) absorber layers with different x values. The effects of S/(S+Se) ratio on the structural, morphological, optical properties of absorber layers and the final performance of the cells are studied in detail. Combining the results of x-ray diffraction and UV-vis spectra, the beneficial band gap grading is considered to exist in the annealed Cu2ZnSn(SxSe1-x)(4) films. The best power conversion efficiency of 4.94% is achieved by pure Cu2ZnSnS4 thin film solar cell with a short circuit current density of 16.82 mA cm(-2) and a high open circuit voltage of 684 mV. (C) 2016 Elsevier B.V. All rights reserved.