Microstructure of Cu(In,Ga)Se 2 Films Deposited in Low Se Vapor Pressure

• Published in: Japanese Journal of Applied Physics Vol. 38; no. 5R; p. 2888
• Main Authors: Shiro Nishiwaki, Shiro Nishiwaki, Naoki Kohara, Naoki Kohara, Takayuki Negami, Takayuki Negami, Hideo Miyake, Hideo Miyake, Takahiro Wada, Takahiro Wada
• Format: Journal Article
• Language: English
• Published: 01.05.1999
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.38.2888

The microstructure of Cu(In,Ga)Se 2 (CIGS) films deposited under low Se flux was studied using scanning electron microscopy, scanning Auger electron spectroscopy and high resolution and analytical electron microscopy. CIGS films were deposited on Mo coated soda-lime glass substrate using the “3-stage” process in which the Se flux used during the third stage was restricted to a forth of standard value. In the as-grown CIGS films, voids were observed along the grain boundaries and a Cu 2 Se phase was identified at the surface and the grain boundaries. The voids and Cu 2 Se layer were produced by vaporization of an In–Se compound from the films during the third stage of deposition. A reaction model on the CIGS grain surface is proposed based on the microstructure observations.