在氩气和氧气混合气氛下,近空间升华法制备了CdTe多晶薄膜。薄膜的结构、性质决定于整个沉积过程。深入研究沉积过程中的热交换、物质输运,有助于获得结构致密具有良好光电性质的CdTe薄膜。分析了近空间沉积的物理机制,测量了近空间沉积装置内的温度分布,讨论了升温过程、气压与薄膜的初期成核的关系。结果表明,不同气压下制备的样品,均有立方相CdTe。此外,还有CdS和SnO2∶F衍射峰。CdTe晶粒随气压增加有减小趋势;随气压的增加,透过率呈下降趋势,相应的CdTe吸收边向短波方向移动。采用衬底温度500 ℃,源温度620 ℃,在120 ℃的温差下,沉积时间4 min上制备CdTe多晶薄膜,获得转换效率优良的结构为SnO2∶F/CdS/CdTe/Au的集成电池。

The structure and characteristics of CdTe thin films are dependent on the whole deposition process in closed-space sublimation system (CSS) in working atmosphere of Ar and O2. It is helpful for preparation of thin and compact CdTe thin films with fine photoelectric characteristics to study the heat exchange and mass transportation in CSS process. Here, the physical mechanism of CSS is analyzed, the temperature distribution in CSS system is measured, and the dependence of preliminary nucleus creation on increasing-temperature process and pressure is studied. The results indicate that the samples depositing in the different pressure are all cubical structure of CdTe with the diffraction peaks of CdS and SnO2∶F. With the gas pressure increasing, the crystal size of CdTe decreases, the transmission of the thin film goes down and the absorption side shifts to the short-wave direction. So the increasing-temperature curve has been optimized, and with the analysis integrated solar cells of better conversion efficiency in configuration of SnO2∶F/CdS/CdTe/Au are achieved.