Antireflection structure of silicon solar cells formed by wet process using catalysis of single nano-sized gold or silver particle

Antireflection nano structure was formed by simple wet chemical etching using catalysis of gold (Au) or silver (Ag) nanoparticle. Single nano-sized particle dispersion solution was coated onto Si(100) substrate with polished surface. Then, the samples were soaked in an aqueous etching solution of hydrofluoric acid and hydrogen peroxide. The surface of etched Si substrate appeared black, and the reflectivity was reduced to below 5% throughout the entire spectrum from 200 to 1000 nm owing to the formed nano structure. The absorption was significantly increased after the formation of antireflection structure, and the conversion efficiency of solar cell with antireflection structure increased from 8.52 to 10.0% owing to the increase of short-circuit current.