Selective self-optical compensation effect for a newly discovered acceptor-associated emission in Zn+ ion-implanted GaAs

Abstract

Photoluminescence measurements were carried out at 2 K for Zn+ ion-implanted GaAs, where the concentration of Zn was widely varied from 3×1016 to 1×1021 cm−3. Two Zn+-associated emissions were formed. One emission is at 1.512 eV, g, and the other emission [g-g] is just below g and this moves towards the lower energy level with increasing Zn concentration, [Zn]. The intensity of [g-g] was enhanced with increasing [Zn], up to [Zn]=3×1017 cm−3, and was gradually suppressed for [Zn] beyond that concentration. This selective self-optical compensation effect (SSOC) for [g-g] was found to occur for moderately heavy ion acceptor species such as Zn and Cd, although [g-g] is a common emission among many other acceptor impurities. In addition two new emissions were observed between g and [g-g] at certain [Zn]. Preliminary theoretical explanations are presented for this SSOC effect.