Photoluminescence of silicon at 1235 nm produced by irradiation of SiO2/Si with Kr+ ions and subsequent high-temperature annealing

The search of ways to improve light-emitting properties of silicon is of great importance for modern optoelectronics. In this work, the photoluminescence (PL) properties of the band at λ = 1235 nm, which appears in silicon upon irradiation of the SiO2/Si system with Kr+ ions followed by annealing at 800 °C, have been studied. It is assumed that the source of PL is a 9R-Si hexagonal phase formed in Si substrate at the interface with SiO2 film. An interpretation is given for the established PL regularities that include the dependencies of PL band intensity on temperature and laser excitation power, as well as the temperature dependence of spectral position of the band maximum. •Photoluminescence band at 1235 nm is observed in Si after Kr irradiation of SiO2/Si.•The 1235 nm band is retained up to the temperatures as high as 80 K.•Emission from 9R-Si phase revealed in Si is assumed to be responsible for this band.•The regularities of band behavior with temperature and excitation power are studied.