Recombination properties of silicon passivated with rare-earth oxide films

Abstract

The recombination properties of silicon passivated with films of rare-earth oxides were investigated. The films were obtained by thermal resistive sputtering of a rare-earth metal followed by thermal oxidation of the obtained layer in air at 400 °C. It was established that the effective nonequilibrium charge-carrier lifetime measured by photoconductivity relaxation is 2–3 times higher after deposition of the rare-earth oxide film. Surface recombination rates at the silicon-rare-earth oxide interface were determined to be 290–730 cm/s for different rare-earth oxides. The combination of high optical transmittance of the experimental materials and low recombination losses in silicon coated with a rare-earth oxide film makes it possible to recommend rare-earth oxide films as optical antireflection and passivating coatings for silicon photoelectric devices.