Application of Taguchi approach to optimize the sol–gel process of the quaternary Cu2ZnSnS4 with good optical properties

Present research deals with the optimal deposition parameters configuration for the synthesis of Cu2ZnSnS4 (CZTS) thin films using the sol–gel method associated to spin coating on ordinary glass substrates without sulfurization. The Taguchi design with a L9 (34) orthogonal array, a signal-to-noise (S/N) ratio and an analysis of variance (ANOVA) are used to optimize the performance characteristic (optical band gap) of CZTS thin films. Four deposition parameters called factors namely the annealing temperature, the annealing time, the ratios Cu/(Zn + Sn) and Zn/Sn were chosen. To conduct the tests using the Taguchi method, three levels were chosen for each factor. The effects of the deposition parameters on structural and optical properties are studied. The determination of the most significant factors of the deposition process on optical properties of as-prepared films is also done. The results showed that the significant parameters are Zn/Sn ratio and the annealing temperature by applying the Taguchi method. •The Taguchi design of experiments is used to optimize the optical band gap of CZTS thin films.•The deposition parameters showed different effects on structural and optical properties.•The films showed for the majority an optical band gap in the range of 1.4–1.6 eV.•The critical factors of the CZTS thin film synthesis by sol–gel method are the Zn/Sn ratio and the annealing temperature.