Nanometer scale fabrication and optical response of InGaN/GaN quantum disks. (15th September 2016)

• Record Type: Journal Article
• Authors: Lai, Yi-Chun; Higo, Akio; Kiba, Takayuki; Thomas, Cedric; Chen, Shula; Lee, Chang Yong; Tanikawa, Tomoyuki; Kuboya, Shigeyuki; Katayama, Ryuji; Shojiki, Kanako; Takayama, Junichi; Yamashita, Ichiro; Murayama, Akihiro; Chi, Gou-Chung; Yu, Peichen; Samukawa, Seiji
• Is Part Of: Nanotechnology. Volume 27:Number 42(2016)
• Publication Date: 2016-09-15
• Subjects: quantum disks -- neutral beam etch -- bio-template -- InGaN/GaN -- single quantum well; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/27/42/425401
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: In this work, we demonstrate homogeneously distributed In0.3 Ga0.7 N/GaN quantum disks (QDs), with an average diameter below 10 nm and a high density of 2.1 × 10 11 cm −2, embedded in 20 nm tall nanopillars. The scalable top-down fabrication process involves the use of self-assembled ferritin bio-templates as the etch mask, spin coated on top of a strained In0.3 Ga0.7 N/GaN single quantum well (SQW) structure, followed by a neutral beam etch (NBE) method. The small dimensions of the iron cores inside ferritin and nearly damage-free process enabled by the NBE jointly contribute to the observation of photoluminescence (PL) from strain-relaxed In0.3 Ga0.7 N/GaN QDs at 6 K. The large blueshift of the peak wavelength by over 70 nm manifests a strong reduction of the quantum-confined Stark effect (QCSE) within the QD structure, which also agrees well with the theoretical prediction using a 3D Schrödinger equation solver. The current results hence pave the way towards the realization of large-scale III-N quantum structures using the combination of bio-templates and NBE, which is vital for the development of next-generation lighting and communication devices.