Process variability in Cu2ZnSnSe4 solar cell devices: Electrical and structural investigations
Faculty of Sciences. Physics
New york :Ieee
Engineering sciences. Technology
The conference record of the IEEE Photovoltaic Specialists Conference / Institute of Electrical and Electronics Engineers. Photovoltaic Specialists Conference [New York, N.Y.] - New York
IEEE 42nd Photovoltaic Specialist Conference (PVSC), JUN 14-19, 2015, New Orleans, LA
, 4 p.
University of Antwerp
We have fabricated 9.7% efficient Cu2ZnSnSe4/CdS/ZnO solar cells by H2Se selenization of sequentially sputtered metal layers. Despite the good efficiency obtained, process control appears to be difficult. In the present contribution we compare the electrical and physical properties of two devices with nominal same fabrication procedure, but 1% and 9.7% power conversion efficiency respectively. We identify the problem of the lower performing device to be the segregation of ZnSe phases at the backside of the sample. This ZnSe seems to be the reason for the strong bias dependent photocurrent observed in the lower performing devices, as it adds a potential barrier for carrier collection. The reason for the different behavior of the two nominally same devices is not fully understood, but speculated to be related to sputtering variability.