EFFECT OF THE EXTRINSIC AND TEMPORAL CARRIERS ON RADIATIVE RECOMBINATION OF III-NITRIDE NANOSTRUCTURES

Abstract

Due to many important applications, the group III-Nitride semiconductors have recently attractedremarkable attention among semiconductor researchers and engineers. In this paper, we report on the impact of extrinsic and temporal carriers on the screening of polarization internal fields. The optical efficiency of GaN/AlGaN multiple quantum well (MQW) nanostructures were studied by means of photoluminescence(PL) and time-resolved PL measurements. Extrinsic carriers come from Si doping in the barriers, whiletemporal carriers originate when the samples are excited by laser beam. The emission peaks of MQWs in PLspectra of the undoped and low-doped samples show a shift towards higher energy levels as excitationintensity increases, while the other samples do not exhibit such a phenomenon due to the dominance of theextrinsic carriers. The transient data confirm the results of the PL measurements.