Broad infrared absorption band through ion beam hyperdoping of silicon with selenium

Abstract

In this work, we present the formation of silicon layers hyperdoped with selenium through Se implantation followed by pulsed laser annealing. The concentration depth distribution of Se atoms was investigated by Rutherford backscattering and X-Ray photoelectron spectroscopies. Scanning tunneling spectroscopy confirmed the formation of intermediate sub-band within Si band gap. The crystallinity of the doped silicon layer and the fraction of Se atoms in Si lattice sites were determined using backscattering yield analysis. Experimental and theoretical sub-band properties were compared and discussed. Notably, a significant increase in light absorption across a wide spectral region (0.2–23.0 μm) was observed, demonstrating the potential of selenium hyperdoping for enhancing infrared absorption in silicon.