Books on thin films technology:

- Handbook of Deposition Technologies for Films and Coatings. Science, Applications and Technology. Peter M. Martin

- Handbook of Thin-Film Deposition Processes and Techniques. Principles, Methods, Equipment and Applications. Krishna Seshan (Ed.)

- Materials Science of Thin Films. Deposition and Structure. Milton Ohring.

- Thin Film Materials Technology. Sputtering of Compound Materials. Kiyotaka Wasa, Makoto Kitabatake and Hideaki Adachi.

These are positions with really detailed description of thin films technology. In some of them you can find also about solar cells.

I hope it will help you.

For thin film solar cells you can refer

"Thin Film Solar Cells" by By K.L. Chopra, S.R. Das, Springer Science & Business Media

Introduction to Surface and Thin Film Processes  by JOHN A. VENABLES