Pulsed laser treatment and photoluminescence of selenium implanted silicon

Abstract

Silicon supersaturated with selenium is a promising material for intermediate-band solar cells and extended infrared photodiodes. Selenium-rich layers were fabricated by Se ion implantation followed by pulsed laser annealing. Rutherford backscattering (RBS) with channeling, Raman scattering, scanning electron and optical microscopy as well as photoluminescence techniques were used for diagnostics of structural and optical properties of Se-rich silicon layers. It has been shown that laser irradiation leads to silicon recrystallization and significant impurity redistribution in the implanted layer. According to the RBS/channeling data, the substitutional fraction of incorporated Se atoms in silicon lattice after laser treatment is 60–80%. Analysis of photoluminescence spectra has been revealed that pulsed laser irradiation of the implanted layer with W = 1.5 J/cm 2 leads to formation of vacancy and interstitial clusters. As the energy in the pulse increases, the bands related with these types of defects disappear from the photoluminescence spectra