title: Large-scale fabrication and luminescence properties of GaN nanostructures by a soft UV-curing nanoimprint lithography.
abstract: GaN nanorods with a period of 400 nm and diameter of 200 nm, and nano-gratings with a period of 400 nm and gap width of 100 nm are fabricated on wafers by a soft UV-curing nanoimprint lithography. These nanostructures show high periodicity and good morphology. The photoluminescence (PL) spectra exhibit that the integral PL intensity of GaN nanorods is enhanced as much as 2.5 times, compared to that of as-grown GaN films. According to finite-difference time-domain simulations and cathodoluminescence mappings, it is concluded that the enhancement for nanorods is due to the improvements of both spontaneous emission rate and light extraction efficiency caused by periodic GaN structures on the surface. By identifying the Raman shift of E1(TO) and E2(H) modes of GaN films with nano-gratings and nanorods, the normal-plane strain ε(zz) is determined. The PL emission energy is found to be proportional to the ε(zz), whose linear proportionality factor is calculated to be -27 meV GPa(-1).
authors.affiliation: Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, People's Republic of China. Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhuang
authors.forename: Xu
authors.initials: X
authors.lastname: Guo
authors.forename: Guogang
authors.initials: G
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Zhi
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
authors.forename: Haixiong
authors.initials: H
authors.lastname: Ge
authors.forename: Fangfang
authors.initials: F
authors.lastname: Ren
authors.forename: Zili
authors.initials: Z
authors.lastname: Xie
authors.forename: Youdou
authors.initials: Y
authors.lastname: Zheng