Optimization of physical properties of spray-deposited Cu_2ZnSnS_4 thin films for solar cell applications

摘要

Cu2ZnSnS4 (CZTS) is a promising material for thin film solar cell applications. On the other hand, spray pyrolysis technique has been identified as a low cost and versatile technique which could reduce cost per watt peak of panels. In this work, the sprayed-CZTS thin films are fabricated at substrate temperature in the range of 340-420 degrees C. The substrate temperature influence on the structural, morphological, electrical and optical properties is evaluated. It is found that CZTS thin films grown under 390 degrees C and thermally treated are the most appropriate for solar cell applications. CZTS thin films with Cu/(Zn + Sn) and Zn/Sn compositional ratios near to the optimal ones are achieved. Finally, resistivity, Hall mobility and carrier density values in the range of 0.5-80.2 Omega.cm, 0.6-10.3 cm(2)/Vs and 2.2 x 10(17)-7.0 x 10(18) cm(-3), respectively, are reported. (C) 2016 Elsevier Ltd. All rights reserved.