The present work reports the effect of gamma-irradiation on the AlInGaN/AlN/GaN heterostructures with different doses: 75 kGy and 150 kGy. The compositional fluctuation and intermixing of the epilayers after gamma irradiation was realized by High Resolution X-ray diffraction. For 75 kGy and 150 kGy samples, the AlInGaN layer was merged with AlN interlayer after gamma irradiation which was realized by simulation fits ω-2θ scans along (0002) plane. The Raman studies showed the degradation in crystalline quality of the gamma-irradiated samples and also confirmed that the alloy compositional fluctuations are due to In(Ga)N-like clusters in the AlInGaN epilayer. The optical properties of the samples were carried out using the room temperature Photoluminescence, which confirms the suppression of In(Ga)N-like clusters after gamma-irradiation. Morphological studies by Atomic Force Microscopy showed decrease in density of the V-pits with increasing gamma-dose. The Hall measurements confirmed the degradation in mobility, carrier concentration and sheet resistance after gamma-irradiation. Though AlInGaN samples underwent heavy doses of gamma-irradiation, the samples showed an electrical response which indicates that they will be suitable for use in harsh environments.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.