Atmospheric pressure dry texturing enabling 20% conversion efficiency on multicrystalline silicon PERC solar cells

Abstract

In this paper, we report significant progress in development and integration of a plasma-less atmospheric pressure dry texturing (ADE) process, performed on multicrystalline silicon (mc-Si) wafers, into high efficiency PERC solar cell architectures using industrially applied process steps. The mechanism of forming sub-micron features on monocrystalline and multicrystalline silicon wafers with commercial grade fluorine gas (F2) is briefly presented. Low weighted surface reflection (Rw,min < 10%) is achieved for mc-Si substrates regardless of the wafer sawing method. Mc-Si PERC solar cells with average conversion efficiencies of 20% are fabricated in the industrial pilot line of Hanwha Q-Cells in Thalheim. A detailed characterization of ADE-textured solar cells suggest that an enhancement in conversion efficiency of up to +0.8% absolute is possible in comparison to the reference-textured solar cells by narrowing the distribution of reflectivity in the textured wafer surface.