Ion-induced secondary electron emission from ZnS thin films deposited by closed-spaced sublimation

► ZnS films of same chemical composition and various energy band gaps were prepared by close-spaced sublimation. ► Ion-induced secondary electron yield of ZnS films was measured. ► Secondary electron yield of ZnS films was quite high as compared to metals. ► Secondary electron yield of ZnS films having same composition was different. ► The dissimilar electron yields are due to the energy band gap, surface barrier potential and density of the films.