Yang Ding-Yu, Xia Geng-Pei, Zheng Jia-Gui, Feng Liang-Huan, Cai Ya-Ping
School of Material Science and Engineering, Sichuan University, Chengdu 610064, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 Jan;29(1):56-61.
In the present paper, the factors of influence on the deposition rate of CdS films prepared by close-spaced sublimation (CSS) were first studied systematically, and it was found from the experiments that the deposition rate increased with the raised temperature of sublimation source, while decreased with the raised substrate temperature and the deposition pressure. The structure, morphology and light transmittance of the prepared samples were tested subsequently, and the results show: (1) The CdS films deposited under different oxygen partial pressure all present predominating growth lattice orientation (103), and further more the films will be strengthened after annealed under CdCl2 atmosphere. (2) The AFM images of CdS show that the films are compact and uniform in grain diameter, and the grain size becomes larger with the increased substrate temperature. Along with it, the film roughness was also augmented. (3) The transmittance in the shortwave region of visible light through the CdS films would be enhanced when its thickness is reduced, and that will help improve the shortwave spectral response of CdTe solar cells. Finally, the prepared CdS films were employed to fabricate CdTe solar cells, which have achieved a conversion efficiency of 10.29%, and thus the feasibility of CSS process in the manufacture of CdTe solar cells was validated primarily.
在本文中，首先系统研究了近空间升华（CSS）法制备CdS薄膜时影响沉积速率的因素，实验发现沉积速率随升华源温度升高而增加，随衬底温度和沉积压力升高而降低。随后对制备样品的结构、形貌和透光率进行了测试，结果表明：（1）在不同氧分压下沉积的CdS薄膜均呈现出占主导的生长晶格取向（103），并且在CdCl2气氛下退火后薄膜会得到强化。（2）CdS的原子力显微镜（AFM）图像表明薄膜致密且粒径均匀，随着衬底温度升高晶粒尺寸变大，同时薄膜粗糙度也增大。（3）当CdS薄膜厚度减小时，其在可见光短波区域的透光率会提高，这将有助于改善碲化镉（CdTe）太阳能电池的短波光谱响应。最后，将制备的CdS薄膜用于制造CdTe太阳能电池，其转换效率达到了10.29%，从而初步验证了CSS工艺在CdTe太阳能电池制造中的可行性。
