升温过程和气压在近空间升华沉积CdTe多晶薄膜中的作用  

Effect of increasing temperature process and atmosphere pressure on CdTe oolv crvstalline thin films in close-spaced sublimation

作　　者：郑华靖[1] 郑家贵[2] 冯良桓[2] 谢二庆[1] 

机构地区：[1]兰州大学物理科学与技术学院,甘肃兰州730000 [2]四川大学材料科学与工程学院,四川成都610064

出　　处：《兰州大学学报（自然科学版）》2006年第2期60-64,共5页Journal of Lanzhou University(Natural Sciences)

基　　金：国家863重点项目(2001AA513010);国家重大基础发展规划(973)资助项目。

摘　　要：近空间升华技术制备 CdTe 多晶薄膜具有薄膜质量好、沉积速率高、设备简单、生产成本低等优点．采用近空间升华法(CSS)制备的 CdTe 多晶薄膜,薄膜的结构、性质与整个沉积过程密切相关,其过程受到较多因素的影响．要实现对沉积过程的控制,必须对沉积过程中的热交换、物质输运进行深入的研究．分析近空间沉积的物理机制,通过对装置内的温度进行测量,对升温曲线进行实验研究,优选了温度分布与升温曲线,研究了气压对 CdTe 薄膜结构、性质的影响．讨论了升温过程、气压与薄膜的初期成核的关系．结果表明：不同气压下沉积的样品均为立方相 CdTe,且还出现 CdS 和 SnO_2∶F 的衍射峰,随着气压增加,CdTe 晶粒减小,薄膜的透过率下降,相应的吸收边向短波方向移动．采用衬底温度500℃,源温度620℃,沉积时间4min 的沉积条件获得了性能优良的 CdTe 多晶薄膜．The closed-space sublimation （CSS） technology is used to prepare CdTe thin films, whose structure and characteristics are closely dependent on the whole deposition process in closed-space sublimation. Because CSS process may be affected by many factors, it is difficult to control the process. Therefore, it is necessary to study the heat exchange and mass transportation in CSS process. In the paper, the physical mechanism of CSS is analyzed and through measuring the temperature distribution and investigating curves of increasing temperature the temperature distribution, the increasing temperature curve have been optimized and the effects of pressure on the structural properties of CdTe thin films analyzed. The results indicate that the samples deposited in different pressures are all of the cubical structure of CdTe and still show the diffraction peaks of CdS and SnO2 ： F. Following the increasing of gas pressure, the crystal size of CdTe minutes and the rate of the transparency of the thin film goes down and the absorption side faces the short-wave direction. The polycrystalline thin films of higher quality are depositing in 4 minutes under the depositing condition, with the substrate temperature being 500℃ and source temperature being 620℃.

关 键 词：CdTe多晶薄膜 近空间升华 太阳电池 升温过程 

分 类 号：TK511[动力工程及工程热物理—热能工程]