采用电子束蒸发的方法在石英基片上一次沉积厚度约为400nm的ZnS与PbS混合薄膜多个样品,随后将不同样品在3×10-3Pa的真空中分别以100~600℃退火1h.样品的成分、结晶性能、表面形貌和光学性质分别采用X射线能量色散谱、X射线衍射仪、扫描电子显微镜、原子力显微镜和分光光度计等进行检测.结果表明,制备态样品为非晶态,300℃真空退火的样品已开始结晶;当退火温度不低于500℃时,退火过程中,混合薄膜中的PbS大量挥发,退火后样品中的PbS含量明显减小.随着退火温度从100℃升高到600℃,样品的表面粗糙度和表面颗粒尺寸是先减小、后增大;光学透射率则呈现先升高后下降再升高的变化特性;退火后混合薄膜光学性质的变化与薄膜的成分、结晶性能和表面形貌的变化密切相关.
ZnS and PbS mixed films with thickness about 400 nm were deposited on quartz substrates by electron beam evaporation.The samples were subsequently annealed in a 3 × 10-3 Pa vacuum at temperatures ranging from 100 ℃ and 600 ℃ for 1 h,respectively.The composition,microstructure,surface morphology,and optical properties of the samples were studying by X-ray energy dispersive spectra,X-ray diffraction,scanning electron microscopy,atomic force microscopy,and spectrophotometer,respectively.The experimental results show that when the annealing temperature is larger than 500 ℃,PbS in the mixed films had been vaporized and PbS content in mixed films is very small.The as-deposited films are amorphous.The samples change into polycrystalline structure after annealing at 300 ℃,and the crystalline performance enhances with the increase of the annealing temperature.When the annealing temperature increases from 100 ℃ to 600 ℃,both the surface roughness and surface grain size of the mixed films decrease first,and then increase.Correspondingly,the transmittance of films increases first,then decreases,and increases last.The variation in transmittance of the annealed films is because of the changes of the film composition,crystalline performance,and surface morphology.