Device optimization for screen printed interdigitated back contact solar cells

Abstract

Two dimensional simulations were performed to asses the potential for screen printed interdigitated back contact solar cells. In this work we optimized the design of the rear back surface field and emitter for screen printed contacts in conjunction with the design of the front surface field for best performance. With these optimized diffusion profiles we then explored the best cell design by varying the pitch, the gap between the n+ and p+ regions and the base resistivity. Model calculations provide guidelines for designing screen printed IBC solar cells given certain limitations on base resistivity or ability to create a small gap between the n+ and p+ diffusion. In these simulations care was taken to assign realistic parameters to cell design, wafer quality, and cell dimensions that are achievable for screen printing technology. Through these simulations we show the potential for a 22% efficient solar cell with screen printed contacts. Higher emitter fraction, smaller gap, and opaque diffused regions play an important role in attaining high efficiency screen printed interdigitated back contact solar cells.