真空共蒸发法制备Cu_xTe薄膜的结构特性分析

Annealing Temperature and Microstructures of Vacuum Co-evaporated Cu_xTe Films

用真空共蒸发法制备了CuxTe(1≤x≤2)薄膜,并通过X射线衍射(XRD)、X射线光电子能谱(XPS)及原子力显微镜(AFM)等表征手段分析了薄膜的结构特性,研究了热处理对不同Cu/Te配比的样品物相转变的影响。结果发现:刚沉积的薄膜非晶结构占主导地位,只有部分低Cu/Te比的薄膜出现多晶结构;退火后,薄膜发生晶相转变,且随着退火温度的升高,不同配比的样品有着不同程度的物相转变。其中,较低配比(x=11、.44)的样品多晶转变较为明显,结晶度较高,说明较小x值的薄膜晶化温度较低,而高x值的薄膜晶化温度较高。用CuxTe薄膜作为背接触层,获得了效率为12.5%的CdS/CdTe小面积太阳电池。

The CuxTe（1≤x≤2） films were grown by vacuum co-evaporation on quartz wafer substrates,and annealed at different temperatures. Its microstructures were characterized with X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and atomic force microscopy（AFM）. The impact of the annealing temperature and stoichiometry of Cu on the phase transition of the films was studied. The results show that the stoichiometry of Cu closely correlates to the phase transition of the films. For instance, after annealing of the as-deposited, amorphous dominant fdms with small x, some polycrystaUine can be observed.As the annealing temperature rises up,the degree of the phase transition markedly varies with x, especially at a small x（x = 1, or 1.44）. We suggest that the crystallization temperature of the film depends on its stoichiometry of Cu;the smaller the x,the higher the crystallization temperature. With CuxTe films as the back contact, the conversion efficiency of the small area CdS/CdTe solar cells was found to be 12.5 %.