Sodalime glass is the most commonly used substrate in fabrication of CIGS thin film solar cells. Small amount of sodium is known to have a favorable effect on device performance; however, an excess amount degrades device performance. The sodium out-diffusion from the sodalime glass is not well-controlled. To obtain the advantages of sodium without losing process control, an alkali barrier layer such as Si_xN_y is deposited before molybdenum layer followed by a sodium precursor. It is essential to optimize thickness of the barrier layer in terms of the ability to effectively avoid the diffusion of sodium from the sodalime glass into the absorber as well as in terms of the adhesion properties of the alkali barrier layer with the sodalime glass substrate. This paper presents effect of Si_xN_y barrier layer thickness on device performance and consequent optimization of thickness.

Date Published: 20 August 2009
PDF: 8 pages
Proc. SPIE 7409, Thin Film Solar Technology, 740911 (20 August 2009); doi: 10.1117/12.826137

Published in SPIE Proceedings Vol. 7409:
Thin Film Solar Technology
Alan E. Delahoy; Louay A. Eldada, Editor(s)