title: Wavelength tunable InGaN/GaN nano-ring LEDs via nano-sphere lithography.
abstract: In this research, nano-ring light-emitting diodes (NRLEDs) with different wall width (120 nm, 80 nm and 40 nm) were fabricated by specialized nano-sphere lithography technology. Through the thinned wall, the effective bandgaps of nano-ring LEDs can be precisely tuned by reducing the strain inside the active region. Photoluminescence (PL) and time-resolved PL measurements indicated the lattice-mismatch induced strain inside the active region was relaxed when the wall width is reduced. Through the simulation, we can understand the strain distribution of active region inside NRLEDs. The simulation results not only revealed the exact distribution of strain but also predicted the trend of wavelength-shifted behavior of NRLEDs. Finally, the NRLEDs devices with four-color emission on the same wafer were demonstrated.
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Sheng-Wen
authors.initials: SW
authors.lastname: Wang
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Kuo-Bin
authors.initials: KB
authors.lastname: Hong
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Tsai
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109, USA.
authors.forename: Chu-Hsiang
authors.initials: CH
authors.lastname: Teng
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: An-Jye
authors.initials: AJ
authors.lastname: Tzou
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: You-Chen
authors.initials: YC
authors.lastname: Chu
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Po-Tsung
authors.initials: PT
authors.lastname: Lee
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109, USA.
authors.forename: Pei-Cheng
authors.initials: PC
authors.lastname: Ku
authors.affiliation: Institute of Photonic System, National Chiao Tung University, Tainan 711, Taiwan.
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Department of Photonics &Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Hao-Chung
authors.initials: HC
authors.lastname: Kuo