Effects of sulphur and tin disulphide vapour treatments of Cu2ZnSnS(Se)4 absorber materials for monograin solar cells

The aim of this study was to find a heat-treatment procedure for monograin powders using a controllable reactive gas phase to improve the CZTS(Se) crystal surface for effectively working p-n junctions. The influence of an isothermal treatment in S and SnS2 vapour on the parameters of monograin layer solar cells is depending on the CZTS(Se) initial composition. The efficiencies of solar cells improve continuously with increasing temperatures of the absorber materials’ post-annealing from 823 to 973K under constant sulphur vapour pressure of 100 Torr. The highest values of Jsc= 18.4 mA/cm2 and Voc= 720 mV were obtained for a device made from CZTS powder annealed at 1013K in SnS2 vapour.