Excitation mechanisms of electro- and photo-luminescence of Er 3+ in Er-implanted Si

Abstract

Er-implanted p +-n Si diode was fabricated and characterized by photo- (PL) and electroluminescence (EL) measurements. A weak EL from Er 3+ was observed at 1538 nm together with the strong free exciton (FE) emissions at 1090 nm and 1130 nm under forward bias, whereas the noisy FE emissions were detected and no noticeable Els from Er 3+ were identified under reverse bias. On the other hands, in PL measurements, a sharp PL signal from Er 3+ was clearly observed at 1538 nm, its PL spectral feature being similar to that of EL from Er 3+ under forward bias. Our present results suggest that the excitation of Er 3+ is achieved through the recombination of electron-hole pairs generated in Si under forward bias.