Electric-arc micro-texturing of silicon surfaces for photovoltaic applications

We demonstrate a novel cost-effective surface micro-texturing method using an electric-arc in argon at atmosphere pressure to enhance light trapping in silicon solar cells. The experimental set-up for electric-arc micro-texturing is described. The morphological, optical and electronic properties of micro-textured silicon surfaces have been investigated. The electronic quality of micro-textured surfaces is studied by measuring the surface minority carrier lifetime (τ_s) to reveal the presence of surface damage, which can be removed by a short chemical etching step. The quality of the electric-arc micro-textured silicon material is recovered as indicated by τ_s. Silicon solar cells are fabricated on such electric-arc micro-textured and chemically etched surfaces. Initial conversion efficiency of 14.4% is achieved which can be further improved. The effective minority carrier lifetime (τ) of the solar cells is examined by observing the open circuit voltage decay, which shows no degradation of τ when compared to chemically micro-textured control samples.