Effects of implantation conditions on the luminescence properties of Eu-doped GaN

Abstract

Europium (Eu) ions were implanted into gallium nitride (GaN) epitaxial layers with doses ranging from 1x 10(13) to 8 x 10(15) cm(-2) at room temperature (RT) to investigate the effects of implantation condition on the photoluminescence (PL) properties. The strong red emission peak from 4f-4f electron transition of Eu3+ is observed at 621 nm after annealing at 1050 degreesC for 30 min in 33% NH3 diluted with N-2. The PL peak intensity at RT is almost the same as those from the near-band-edge emission of GaN. The PL intensity increases with increasing Eu dose up to 3 x 10(14) cm(-2), but saturates around 1 x 10(15) cm(-2). At doses above 1 x 10(15) cm(-2), the PL intensity decreases with increasing Eu concentration. The reasons for the decrease in PL intensity can be interpreted in terms of the concentration quenching due to high Eu concentration as well as residual damage created by implantation. (C) 2003 Elsevier Science B.V. All rights reserved.