Recombination limits open-circuit voltages in thin film photovoltaic (PV) devices to 60-65% of the thermodynamic limit. The project will develop fast, non-contact optical metrology methods to detect optically active defects in thin-film photovoltaic (PV) materials and map recombination velocities at shallow interfaces. These techniques will speed up the diagnostics and optimization of thin-film PV absorber materials and interfaces.
Researchers will develop excitation spectroscopy to enable identification of the lifetime and voltage-limiting defects in thin-film PV absorbers. Single- and two-photon time-resolved photoluminescence (TRPL) will be combined with second harmonics generation (SHG) microscopy to enable lifetime mapping at the diffraction limit.
By developing and applying new optical probes and transferring this knowledge to the PV industry, this research will enable higher PV efficiency and allow for more rapid adoption of thin film PV technologies. This project will advance fundamental understanding and device applications of cadmium telluride (CdTe) and copper indium gallium selenide (CIGS) PV.