High aspect ratio triangular front contacts for solar cells fabricated by string‐printing

Abstract

AbstractWe are presenting a novel method to fabricate high aspect ratio, triangular cross‐section solar cell front contacts, henceforth referred to as string‐printing. We optimized string‐printing to yield contacts with an aspect ratio larger than 1 and a light redirection efficiency or effective transparency of 67%, thereby mitigating most of the optical losses inherent to flat metallic front grids. In string‐printing, a string coated with silver paste approaches a substrate until contact is made. Withdrawing the string then leaves behind silver paste on the substrate. Here, we describe the fabrication method and show initial results including current density‐voltage curves of string‐printed silicon heterojunction solar cells, as well as the effective transparencies of the contacts. String‐printing is a scalable, low‐temperature process with high potential to boost commercial solar cell efficiency and lower the module price per Watt.