Capacitance analysis of wire-array solar cell

Solar cell texturized with wire-array structure is an emerging solar cell architecture that promises to improve the performance of low-cost but low lifetime solar materials. Central to this idea is conformal (radial) cylindrical p-n junction geometry that allows radial carrier collection orthogonal to the light absorption direction. Despite many efforts to produce wire-array solar cells so far there have been no known method to identify the presence of this conformal junction. In this paper we demonstrate unique capacitance voltage analysis to determine the junction structures in the wire-array solar cells and successfully identify which cell that offers best performance. This method also provides a novel way to determine solar cell junction depth via simple C-V analysis and thus can be utilized as a process monitor in the emitter formation step of standard (planar) solar cells. The method and analysis described here are critical to realize a performance-enhancing wire-array solar cell.