Cu2ZnSnS4 Thin Films Synthesized by Cosputtering and Rapid Thermal Annealing: Effects of Composition and Temperature

In this paper we study the structural properties of Cu
₂
ZnSnS
₄
(CZTS) synthesized by cosputtering binary sulfide followed rapid thermal annealing (RTA) as functions of temperature and composition. By annealing identical samples at different temperatures we were able to find the optimum temperature for annealing samples in our RTA furnace. With this information, we annealed samples with a variety of discrete compositions at the optimum temperature to study the compositional differences on the optical, electrical and the structural differences on CZTS thin film crystallization. Samples were evaluated by 1-ray diffraction, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Sample rich in Cu tended to form areas of Cu
_2-1
S. It was confirmed that Sn loss during annealing increases with increased annealing temperature. Samples rich in tin before annealing grew larger grains indicating that Sn can also play a role in grain growth.