|Surface characterization of epitaxial Cu-rich CuInSe2 absorbers|
|Evandro M. Lanzoni, Conrad Spindler, Omar Ramirez, Michele Melchiorre, Susanne Siebentritt, Alex Redinger
University of Luxembourg, Luxembourg, Luxembourg
In this work, we investigated the electrical properties of epitaxial Cu-rich CuInSe2 by frequency modulation Kelvin probe force microscopy (FM-KPFM) in ultra-high vacuum. We observed a work function dependence according to the surface orientation of the Cu-rich CIS crystal. Additionally, we analyze the sample surface after the conventional procedure of KCN etching. Our results show the possibility to increase the efficiency of epitaxial Cu-rich CuInSe2 by growing the materials in the appropriated surface orientation where the variations in work function are reduced.