Characterization of Photovoltaics: From Cells Properties to Atoms

Photovoltaics are an attractive option to supplement our nations energy supply as they provide continuous power under illumination throughout the lifetime of the device. Making these devices as efficient as possible will inevitably increase their presence in the market as the installation cost to power return ratio will increase. The reality is that the majority of PV technologies have been extensively studied over the last several decades and for many the slope of the efficiency vs. time curve has drastically decreased. Research is now focused on making small improvements in device efficiency. Efficiency measurements provide feedback on the quality of the entire device structure but ultimately device properties are determined at the atomic scale through the interaction of charge carriers and defects. In order to determine how defects are related to the discrepancy between theoretical and actual device efficiency it is necessary to employ a suite of characterization techniques that vary in scale from centimeters to angstroms.