Thin Film Solar Cells:
Thin film solar cells are an exciting photovoltaic (PV) technology in the market today, where a thin PV layer (< 5 µm) can absorb over 90% of sunlight. This attractive technique, however, has shown a module efficiency of 10 %, still well below the theoretical maximum value of 30 % for CdTe. It has been suggested that the absorber doping, microstructural properties (e.g., grain interior, grain boundaries), p-n junction interfaces, and/or back-contacts could be responsible for the limited performance. Our group focuses on the local PV characterizations of microstructures and correlates the inhomogeneity to device performance.
Radial Junction Pillar Array Solar Cells:
Sunlight is an abundant renewable energy source, providing 10,000 times more energy than the world’s current total energy use. A key metric of solar cells is power conversion efficiency, the ratio of the electrical output of a solar cell to the incident sunlight. Next generation solar cells use novel device architectures and inexpensive PV materials. For instance, an array of radial junction solar cell enables decoupling of the direction of light absorption to photo-generated carrier collection, enhancing its PV performance in comparison to planar controls.