On the effect of stoichiometry and oxygen on the properties of CuInSe2 thin films and devices

✍ Scribed by R. Noufi; R.C. Powell; R.J. Matson

• Publisher: Elsevier Science
• Year: 1987
• Weight: 949 KB
• Volume: 21
• Category: Article
• ISSN: 0379-6787
• DOI: 10.1016/0379-6787(87)90104-9

✦ Synopsis

The electrical characteristics of CuInSe 2 thin films and CdS/CuInSe 2 devices have been shown to be controlled by the stoichiometry. Off-stoichiometric films that are employed in the device (i.e. copper-poor and seleniumpoor compositions) are rich in native defects such as Vcu (acceptor), Incu and In i (donors) and Vs~ (donor) and are highly compensated. During an air anneal, oxygen can interact with the donor defects, reducing their density and making the material more p type. In certain intrinsic or slightly p-type films, interaction with oxygen can convert the conductivity type. The oxygen is probably strongly chemisorbed, or else it forms coordinated bonds with Incu on the grain surfaces. It can be removed either by chemical reducing agents such as hydrazine or by an electron beam.