Advancements in silicon buried contact solar cells

Abstract

Large-area laser-grooved concentrator cells of 22-23% efficiency at 20 suns are described. The role of laser texturing in forming macrogrooves in the surface is examined, particularly with reference to their abilities to reduce reflection, reduce emitter resistive losses, and increase the effective minority carrier diffusion lengths of the substrate. An overview is given of the application of the laser grooving and texturing approaches to polycrystalline substrates. A new generation of buried contact solar cells is described with emphasis on the identified structural changes believed capable of producing short-term efficiency improvements at 1 sun to 23% and in the long term to 25%.<>