Cu_2Sn(S,Se)_3薄膜的溶液法制备及其光电性能研究

Photoelectric properties of Cu_2Sn(S,Se)_3 films prepared by solution method

采用低廉、简便及易于控制元素组成的溶液法在钠钙玻璃和钼玻璃基底上沉积Cu-Sn-S前驱体膜,随后在N_2保护下硒化获得到Cu_2Sn(S,Se)_3薄膜,并通过调控前驱薄膜的硒化退火温度,实现了对薄膜形貌、物相结构、电学及光学性能的有效调制.研究结果表明,适当的硒化退火温度,如480℃,可得到表面平整、结晶度高、晶粒致密和双层结构(上层大、下层小晶粒)的Cu_2Sn(S,Se)_3薄膜,其带隙为1.28 eV,载流子浓度可低至6.780×10^(17) cm^(-3),迁移率高达18.19 cm^2·V^(-1)·S^(-1),可用于薄膜太阳能电池的光吸收层.

In this work,Cu-Sn-S precursor film was prepared on a soda lime glass and molybdenum glass substrate by solution method,and then a Cu2Sn(S,Se)3 film was obtained by selenization of the precursor under N 2 protection.The morphology,phase,optical and electrical properties of Cu2Sn(S,Se)3 films were effectively controlled by adjusting the annealing temperature of the precursor films.It is found that,under an appropriate annealing temperature of 480 ℃ in the selenization process, Cu2Sn(S,Se)3 film with double-layer structure show a flat surface,high crystallinity,dense grains and a direct band-gap of 1.28 eV.Furthermore,its carrier concentration can be reduced to 6.780×10 17 cm^-3 and the mobility can be as high as 18.19 cm^2 ·V^-1 ·S^-1 ,which is suitable for the optical absorption layer of thin-film solar cells.