The Zn-rich and Cu-poor Cu2ZnSnSe4 (CZTSe) thin films were produced on flexible Mo foil by the three-step process. The XRD analysis demonstrates that the film mainly consists of CZTSe tetragonal phase and can contained ZnSe secondary phase. In addition, there are reflections of Mo and MoSe2. It was found that the crystal structure of the CZTSe films deposited on a Mo foil substrate was stable at low temperatures. The lattice parameters a and c are linearly decreasing in rang 5.707–5.637 and 11.394–11.298 A, respectively, with a change in the temperature of the X-ray measurements from the 300 to 100 K. The thermal expansion coefficient is 9.87 ? 10–6 K–1