Byungha Shin1, Oki Gunawan1, Yu Zhu1, N. A. Bojarczuk1, S. Jay Chey1, Supratik Guha1
1IBM T.J. Watson Research Center, Yorktown Heights, NY 10598, USA;
Tóm tắt
ABSTRACTUsing vacuum process, we fabricated Cu2ZnSnS4 solar cells with 8.4% efficiency, a number independently certified by an external, accredited laboratory. This is the highest efficiency reported for pure sulfide Cu2ZnSnS4 prepared by any method. Consistent with literature, the optimal composition is Cu‐poor and Zn‐rich despite the precipitation of secondary phases (e.g., ZnS). Despite a very thin absorber thickness (~600 nm), a reasonably good short‐circuit current was obtained. Time‐resolved photoluminescence measurements suggest a minority carrier‐diffusion length on the order of several hundreds of nanometers and relatively good collection of photo‐carriers across the entire absorber thickness. Copyright © 2011 John Wiley & Sons, Ltd.
