Fabrications of SnS thin films and SnS-based heterojunctions on flexible polyimide substrates

Abstract

The flexible polyimide substrates were utilized to realize the flexibility of SnS thin films and SnS-based heterojunctions. The SnS thin films and ZnO/SnS heterojunctions were deposited on polyimide substrates by magnetron sputtering. The properties of SnS thin films and ZnO/SnS heterojunctions were studied. The experimental results show that the post annealing can enhance the degree of crystallinity of flexible SnS thin films. The annealed SnS thin films present polycrystalline structure with preferential orientation along the (040) plane and grain size of 18 nm. The compositions of as-deposited and annealed flexible SnS thin films are close to the stoichiometry of SnS. The direct band gaps are 1.48 and 1.32 eV for the as-deposited and annealed SnS thin films, respectively. The fabricated flexible ZnO/SnS heterojunctions show rectifying properties with the rectifying ratio of 6.85 and the diode ideal factor of 1.23. The experimental results indicate the feasibility of using polyimide as the substrates of SnS thin films and SnS-based heterojunctions.