This is the second Knowledge Sharing report for UNSW’s Development of Beyond 20% Efficiency Kesterite (CZTSSe) Solar Cells project.
Report extract
The epitaxial grown ZnSe nano layer has very small lattice mismatch with CZTSe (1.04%), which enables a strain free interface. The relatively high conduction band and low valance band of ZnSe thus renders perfect surface passivation effect.
As long as the thickness of this ZnSe layer is limited to several nanometres, the electron transport is not limited due to thermal-assisted tunnelling process.