Assessing local voltage in CIGS solar cells by nanoscale resolved Kelvin Probe Force Microscopy and sub-micron photoluminescence

Here we use nanoscale resolved Kelvin Probe Force Microscopy (KPFM) to locally probe the open circuit voltage in CIGS thin film solar cells. Illumination-dependent KPFM shows that the grain boundaries and grain cores present variations in surface photovoltage, as a consequence of the local variation of the open circuit voltage. Additionally, room temperature sub-micron photoluminescence (PL) scans were used to map the recombination centers in the polycrystalline CIGS films.