Earth Abundant Thin Film Absorbers and Solar Cells
ABSTRACT :
Next to Si solar cells, the CdTe and CuInGaSe2 thin film solar cells had come out with remarkable cell efficiencies of 20.4 % and 22.6 %, and reached 1 GW/yr production level. To meet world’s multi terawatt challenge, the cost and scarcity of ‘In’ and ‘Te’ as well as the toxicity of Cd, are major barriers for widespread utilization. In this context, Kesterites, Cu2ZnSnS4 have been extensively studied as an alternative and demonstrated 12.6 % conversion efficiency over the decade of research. Attainment of efficiencies over 15 % would be challenging because of the complex phase chemistry, defect physics and interface science associated with quaternary/pentanary compounds. Hence, it is high time to explore new technologies. The presentation includes work on growth kinetics of CZTS thin films and solar cells, several key reasons for low performance and the design of emerging absorbers with suitable photovoltaic properties for high efficient devices.