采用磁控溅射法，在衬底温度300 ℃制备CdS薄膜，并选取370 ℃、380 ℃、390℃三个温度退火，获得在干燥空气和CdCl2源+干燥空气两种气氛下退火的CdS薄膜.通过研究热处理前后CdS薄膜的形貌、结构和光学性能表明，CdS薄膜在干燥空气中退火，晶粒度、表面粗糙度和可见光透过率变化不明显，光学带隙随退火温度的升高而增大; 在CdCl2源+干燥空气中退火，随退火温度的升高发生明显的再结晶和晶粒长大，表面粗糙度增大，可见光透过率和光学带隙随退火温度的升高而减小.分析得出: 上述性能的改变是由于不同的退火条件对CdS薄膜的再结晶温度和带尾态掺杂浓度改变的结果.

CdS thin films are deposited on the substrate temperature of 300 ℃ by magnetron sputtering. The deposited films are annealed at temperature of 370℃, 380 ℃ and 390 ℃ respectively in two atmosphere of dry air and CdCl2 source +dry air. The morphology, structure and optical properties before and after thermal annealing are investigated. The results show that annealed in dry air, grain size, surface roughness and visible light transmittance change is not obvious, the optical band gap increases with temperature increasing. Annealed in CdCl2 source + dry air, recrystallization and grain growth are significant, surface roughness increases, visible light transmittance and optical band gap decreases with temperature increasing. Analysis revealed that the performance is the results of recrystallization temperature and the band tail states doping concentration changes at different annealing conditions.CdS thin films were deposited on the substrate at temperature of 300 ℃ by magnetron sputtering. The deposited films were annealed at temperature of 370℃, 380 ℃ and 390 ℃, respectively, in either atmosphere of dry air or a mixture of CdCl2 and dry air. The morphology, structure and optical properties before and after thermal annealing were investigated. The results show that for samples annealed in dry air, the variations of grain size, surface roughness and visible light transmittance with annealing temperature are not obvious, while the optical band gap increases with temperature increasing. Annealed in the mixture of CdCl2 and dry air, recrystallization and grain growth in the samples are significant. Surface roughness increases with temperature increasing, on the contrary, visible light transmittance and optical band gap decreases. These phenomena are the results of changes in the temperature of recrystallization and doping concentration in the band tail states at different annealing atmosphere.