Effect of the in-air heat treatment in the phase formation and morphology of electrospun Cu2ZnSnS4 fibers

Cu2ZnSnS4 was successfully synthesized by the electrospinning process using thiourea as the sulfur source and heat treated in air without further sulfurization. The XRD and Raman spectroscopy investigation of heat treatments showed a good synthesis of Cu2ZnSnS4 film at a temperature of 400 °C. Scanning electron microscopy (SEM) revealed a homogeneous and compact film. The optical band gap was around 2.2 eV and the main secondary products formed were binary sulfides and oxides.