Evidence of Silicon Band-Edge Emission Enhancement When Interfaced with SiO$_{2}$:Er Films

Abstract

Nearly two-orders of magnitude increase in room-temperature band-to-band (1.067 eV) infrared emission from crystalline silicon, coated with erbium-doped sol-gel films, have been achieved. Phonon-assisted band-to-band emission from coated and annealed p-Si is strongest for the sample annealed at 700$^{\circ}$C. In this paper, evidence of the origin of the emission band from the band edge recombination activities is established. Enhancement of radiative recombination of free carriers is reasoned by stresses at the interface due to the annealed sol-gel deposited silica. Comparative studies with other strained silicon samples are presented.