Exploring swift-heavy ion irradiation of InGaN/GaN multiple quantum wells for green-emitters: the use of Raman and photoluminescence to assess the irradiation effects on the optical and structural properties

Abstract

Xe SHI irradiation of InGaN/GaN MQWs leads to surface damage and intermixing at the interfaces. The introduced defects cause a strong quenching of the luminescence as well as a change in the excitation mechanisms.

Damage in InGaN/GaN bilayers upon Xe and Pb swift heavy ion irradiation

“…Further investigation is necessary to pinpoint the reason for the pronounced defect gradient within InGaN. Enhanced surface damage has been observed in Molecular Dynamics simulations in GaN 3 and by Raman and RBS/C in InGaN/GaN quantum well structures, 34 however, in much shallower regions than observed here. The effect of surface roughness and voids on aligned RBS/C spectra is difficult to evaluate and is currently not implemented in the McChasy code and may lead to some artifacts.…”

“…Understanding the effects of SHI irradiation is important, e.g., for the potential application of InGaN-based devices in space technology. 2,30,31 Among the studies on defects in InGaN, the majority have considered either very thin layers of InGaN (those of thickness not exceeding a few nm) as in the case of multi-quantum wells [32][33][34][35][36] or thicker layers (those of thickness exceeding a few tens of nm) mainly upon bombardment using MEIs, concluding that InGaN reveals higher damage level than GaN due to less efficient dynamic annealing. 2,37 However, thick InGaN layers are promising in electronic device technology, e.g., to lower the overvoltage in green, orange, and red nitride-based LEDs and thereby improve device efficiency.…”