Zn沉积时间对低温硫化制备ZnS薄膜性能的影响

采用磁控溅射方法在不同时间下沉积了Zn薄膜,接着先后在200℃和400℃温度下的硫蒸气和氩气氛中进行了低温硫化退火,时间都为1 h,最后得到不同厚度的六方相ZnS薄膜。以XRD、SEM、EDS和紫外可见分光光度计对薄膜进行表征。研究表明:随着Zn沉积时间的增加,硫化制备的ZnS薄膜的晶粒尺寸、光透过率、带隙、S/Zn摩尔比都发生了明显变化,但变化趋势不同。并且,对其低温硫化生长ZnS薄膜的机理进行了讨论。此外,硫化前的抽真空处理可以明显改善ZnS薄膜的质量。所有低温硫化制备的ZnS薄膜在400~1100 nm范围光透过率约为70%,带隙值为3.49~3.57 eV。其中,3 min沉积的Zn在抽真空后低温硫化生长的ZnS薄膜质量最佳。

Effect of deposition time of Zn on properties of ZnS thin films prepared by low-temperature sulfidation

Zn thin films were deposited for different time by magnetron sputtering. These Zn thin films were preheated at 200 ℃ for 1 h and subsequently annealed at 400 ℃ for 1 h in an atmosphere of sulfur-vapor and Ar. The properties of the samples were analyzed by XRD(X-ray diffractometer), SEM(scanning electron microscopy), EDS(Energy Dispersive Spectrometer) and UV-VIS spectrophotometer. The results show that with increasing deposition time of Zn, the grain size, optical transmittance, band-gap, and S/Zn molar ratio of ZnS thin films were obviously changed. The low-temperature sulfidation mechanism of these ZnS thin films was also discussed.Besides, the evacuation before sulfidation can evidently improve the qualities of ZnS thin films. All ZnS thin films exhibit the optical transparency of about 70% in the 400-1100 nm region and band-gap energies from 3.49 eV to 3.57 eV. The best quality ZnS thin films were prepared by an evacuation, followed by low-temperature sulfidation of the 3 min-deposited Zn.