Fabrication and Characterization of Screen-Printed Cu2ZnSnS4 Films for Photovoltaic Applications

Cu2ZnSnS4 (CZTS) is deemed to be one of the most promising photovoltaic materials due to its properties such as tunable band gap energy of 1.4-1.6eV and an absorption coefficient greater than 10(4) cm(-1). In the present work, CZTS films were deposited onto glass substrate by a less complex and cost efficient screen-printing method and thereafter sintered. The structural, morphological, optical and electrical properties of CZTS films were studied. The x-ray diffraction and Raman studies show that the screen-printed CZTS films were indexed to a single phase kesterite structure. The morphology of the films was examined through scanning electron microscopy. The EDAX analysis indicates the presence of Cu, Zn, Sn, and S elements in the films. Direct type band gap of 1.51eV was found for the films, which is quite close to the optimum band gap, i.e., between 1.4eV and 1.5eV required for a solar absorber layer. The dark electrical resistivity of films was found to be of the order of 10(2) -cm as evaluated by the two probe method.