Modeling performance of three-dimensional nanojunction photovoltaic devices

We present an analytical approach for modeling the device physics of three-dimensionally nanostructured devices. The approach for the first time describes three-dimensional diffusion as well as distinguishes between isolated and interdigitated pn junction devices. The modeling technique can be applied to various device architectures, including isolated radial pn junctions, inverted grain boundary junctions, point-contact nanojunctions, and extended nanojunctions. As a test case, we use low quality material properties of CdTe to show that the solar power conversion efficiencies of the nanojunction designs are superior to that of the planar junction, with the extended nanojunction geometry performing the best.