Regulation of surface texturization through copper-assisted chemical etching for silicon solar cells

Various structures were fabricated through a copper-assisted chemical etching method for texturization of monocrystalline silicon solar cells, including nanopore, inverted pyramid, V-groove, upright pyramid and hybrid structures. Structural characteristics, etching processes and anti-reflection abilities of the textured structures were systematically analyzed. Brand new texturization results were observed in this research. A possibility that the copper-catalyzed textured structures can be terminated with silicon {1 1 0} crystalline planes is proposed, and the evidence is provided. Furthermore, the transformation of the textured structures was studied, and the agglomerated behavior of the copper nanoparticles deposited on the silicon surface during etching was demonstrated to be a prominent source for the formation of various textured structures. The influences of etchant components and initial silicon surface states on the agglomeration were also studied. Consequently, the surface morphology and anti-reflection property of the textured silicon wafers can be well regulated by controlling the agglomeration of deposited copper nanoparticles in the etching process. A minimum average reflectance of 6.19% in the wavelength range of 300–1000 nm was obtained, which indicates great potentials of this copper-assisted texturization process for the photovoltaic application. In addition, according to the experimental results and analyses, a practical guidance for texturization of silicon solar cells is provided.