Imaging of a Polycrystalline Silicon Solar Cell Using a Laser Terahertz Emission Microscope

Abstract

We employed a laser terahertz (THz) emission microscope (LTEM) as a novel tool for evaluating solar cells. LTEM images are obtained by exciting a polycrystalline silicon solar cell with femtosecond laser illumination and visualizing the local distribution of the optical response. THz emission signals also provide various types of information, such as the screening effect of the built-in electrical field near pn junctions. These results indicate that this technique can be used to evaluate the local photoelectric conversion efficiency distribution and dynamic behavior of optically excited carriers in solar cells.