@inproceedings{845d35bb9f364aa1a776b02ecf8b5103,
title = "Highly efficient transverse-electric-dominant ultraviolet-C emitters employing GaN multiple quantum disks in AlN nanowire matrix",
abstract = "Heavy reliance on extensively studied AlGaN based light emitting diodes (LEDs) to replace environmentally hazardous mercury based ultraviolet (UV) lamps is inevitable. However, external quantum efficiency (EQE) for AlGaN based deep UV emitters remains poor. Dislocation induced nonradiative recombination centers and poor electron-hole wavefunction overlap due to the large polarization field induced quantum confined stark effect (QCSE) in {"}Al{"}rich AlGaN are some of the key factors responsible for poor EQE. In addition, the transverse electric polarized light is extremely suppressed in {"}Al{"}-rich AlGaN quantum wells (QWs) because of the undesired crossing over among the light hole (LH), heavy hole (HH) and crystal-field split-off (SH) states. Here, optical and structural integrities of dislocation-free ultrathin GaN quantum disk (QDisk) (∼ 1.2 nm) embedded in AlN barrier (∼ 3 nm) grown employing plasma-assisted molecular beam epitaxy (PAMBE) are investigated considering it as a novel nanostructure to realize highly efficient TE polarized deep UV emitters. The structural and chemical integrities of thus grown QDisks are investigated by high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). We, particularly, emphasize the polarization dependent photoluminescence (PL) study of the GaN Disks to accomplish almost purely TE polarized UV (∼ 260 nm) light. In addition, we observed significantly high internal quantum efficiency (IQE) of ∼ 80 %, which is attributed to the enhanced overlap of the electron-hole wavefunction in extremely quantum confined ultrathin GaN QDisks, thereby presenting GaN QDisks embedded in AlN nanowires as a practical pathway towards the efficient deep UV emitters.",
keywords = "Deep-ultraviolet emission, GaN quantum disks, epitaxial growth, quantum confinement, transverse-electric-emission",
author = "Subedi, {Ram Chandra} and Min, {Jung Wook} and Somak Mitra and Li, {Kuang Hui} and Idris Ajia and Edgars Stegenburgs and Anjum, {Dalaver H.} and Michele Conroy and Kalani Moore and Ursel Bangert and Roqan, {Iman S.} and Ng, {Tien Khee} and Ooi, {Boon S.}",
note = "Publisher Copyright: {\textcopyright} 2021 SPIE.; Gallium Nitride Materials and Devices XVI 2021 ; Conference date: 06-03-2021 Through 11-03-2021",
year = "2021",
doi = "10.1117/12.2576596",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Hiroshi Fujioka and Hadis Morkoc and Schwarz, {Ulrich T.}",
booktitle = "Gallium Nitride Materials and Devices XVI",
}