退火对ZnS薄膜光学性质和结构的影响

Effects of Annealing on Optical Properties and Structure of ZnS Thin Film Prepared by Vacuum Evaporation

采用真空蒸发法在石英基片上制备了ZnS薄膜,把制备好的ZnS薄膜进行退火处理,温度从300℃到900℃,退火时间为1h.利用扫描电镜(SEM)研究了薄膜厚度随退火温度的变化,利用光致发光谱(PL)和光吸收研究了在不同退火温度处理下薄膜光学性质的变化.结果显示,700℃随退火温度的升高,薄膜厚度变小,而700℃以后,随退火温度的升高薄膜厚度变大.光吸收显示,随退火温度的升高,薄膜在可见光范围内的光吸收逐渐降低,光学带宽发生蓝移,700℃以后,随退火温度身高,光吸收有一定的升高,光学带宽发生红移.光致发光显示,随退火温度的升高,ZnS薄膜与深能级缺陷相关的发光带(DLE)增强,700℃后薄膜,随退火温度的升高,DLE减弱.

We prepared ZnS thin film on quartz glass substrate using vacuum evaporation technology.Then we annealed the film at different temperatures that vary in the range of 300-900℃.At different temperatures,the properties of the film such as film thickness,absorption coefficient and energy band gap were investigated by Scanning Electron Microscope（SEM）,UV-Vis transmission and photoluminescence（PL）.Our results show that the thickness reduced,the optical absorption in the visible region increased while the absorption edge blueshifted with increasing annealing temperature from 300-700℃.But after 700℃,the thickness increased,the optical absorption in the visible region reduced while the absorption edge redshifted as the annealing temperature increases.At the same time,with increasing annealing temperature from 300-700℃,the deep level emission（DEL）in photoluminescence spectrum enhanced while it weakened when the temperature is above 700℃.