Fast and low-temperature sputtering epitaxy of Si and Ge and its application to optoelectronics

Abstract

Novel Si/SiGex-Ge multi-junction solar cell structure was proposed, and pin junction Ge solar cell was fabricated on Ge substrate by sputter epitaxy for the first time, in which growth temperature was under 360°C and growth rates was ~2 nm/s. Internal quantum efficiency at infrared wavelength was as high as 76%, with an open circuit voltage of 0.15V.