Determination of Mg acceptor concentration in GaN through photoluminescence

Abstract

Herein, we report on a photoluminescence (PL) method for evaluating the Mg acceptor concentration in GaN, which has thus far been difficult and costly to determine using conventional electrical methods. The proposed method is based on the intensity ratio between the acceptor bound exciton emission and free exciton emission in the PL spectra of GaN. The calibration curve for the Mg acceptor concentration ranging from 6.4 × 1016 to 1.2 × 1018 cm−3 was obtained from the concentration dependence of the PL spectra recorded at 40 K. Furthermore, the detection limit of the Mg acceptor concentration from this method was estimated to be approximately 1010 cm−3. Results indicate that our method enables the unambiguous, simple, low-cost, and nondestructive quantification of the Mg acceptor concentration of p-type GaN, which is important in power device applications.