Temperature‐dependent cathodoluminescence investigation of Er‐implanted GaN thin films

Abstract

In this paper, temperature‐dependent cathodoluminescence (CL) spectra of Er‐implanted GaN thin films were measured. The effects of accelerating voltage and temperature on the CL spectra of Er‐implanted GaN were investigated. In the near band‐edge emission region, the competition mechanism between DAP and D0X was disclosed. A slight blue shift of the DAP emission peak with the increase of accelerating voltage was observed. The temperature dependence of the CL intensity of FX emission reveals a binding energy of ∼32 meV in Er‐implanted GaN. Below 182 K, the 2H11/2 state of Er3+ is not thermally populated and the yellow band luminescence (YL) related to the defects was observed. At higher temperature, the thermal coupling between the two excited state levels of 2H11/2 and 4S3/2 of Er3+ is obvious and the YL is nearly invisible. Even at 373 K, a strong green emission at 537 nm can be observed, which indicates the Er‐doped GaN is promising to be applied in high‐temperature environments.