Atomistic modeling of nonpolar m-plane InGaN disk-in-wire light emitters

Abstract

InGaN heterostructures, when grown along the polar c-plane orientation, are prone to large internal polarization fields, which significantly affect their electronic bandstructure and optical properties and result in poor quantum efficiency. In this regard, devices grown in nonpolar crystal orientations (with zero spontaneous polarization) are promising and were reported to exhibit higher efficiency. In this paper, we first present the numerical implementation of wurtzite nonpolar m-plane crystallographic orientation within a 10-band $$sp^{3}s^{*}$$ (with spin) tight-binding formalism as available in the atomistic three-dimensional Nanoelectronic Modeling (NEMO 3-D) toolkit. In conjunction with a TCAD simulator, we then evaluate and compare the performance of $$\hbox {In}_{0.25}\hbox {Ga}_{0.75}\hbox {N/GaN}$$ disk-in-wire light-emitting diodes in c-plane and m-plane crystallographic orientations in terms of polarization fields, electronic bandstructure, interband optical transition rates, and internal quantum efficiency (IQE). In contrast to bulk and quantum well structures m-plane, where the net polarization potential is ideally zero, the disk-in-wire configuration considered in this study exhibits a small internal potential. Overall, the m-plane structure, as compared to the c-plane counterpart, offers higher spontaneous emission rate and IQE as well as an improved efficiency droop characteristic.