title: Ultraviolet Electroluminescence from ZnS@ZnO Core-Shell Nanowires/p-GaN Introduced by Exciton Localization.
abstract: We investigate the electroluminescence (EL) from light emitting diodes (LEDs) of ZnO nanowires/p-GaN structure and ZnS@ZnO core-shell nanowires/p-GaN structure. With the increase of forward bias, the emission peak of ZnO nanowires/p-GaN structure heterojunction shows a blue-shift, while the ZnS@ZnO core-shell nanowires/p-GaN structure demonstrates a changing EL emission; the ultraviolet (UV) emission at 378 nm can be observed. This discrepancy is related to the localized states introduced by ZnS particles, which results in a different carrier recombination process near the interfaces of the heterojunction. The localized states capture the carriers in ZnO nanowires and convert them to localized excitons under high forward bias. A strong UV emission due to localized excitons can be observed. Our results indicated that utilizing localized excitons should be a new route toward ZnO-based ultraviolet LEDs with high efficiency.
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Fang
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Department of Electrical and Electronic Engineering, South University of Science and Technology of China , Shenzhen, Guangdong 518055, P. R. China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Electrical and Electronic Engineering, South University of Science and Technology of China , Shenzhen, Guangdong 518055, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.affiliation: Key Laboratory of Physics and Technology for Advanced Batteries, Ministry of Education, College of Physics, JilinUniversity , Changchun 130012, P. R. China.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Jilong
authors.initials: J
authors.lastname: Tang
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Dan
authors.initials: D
authors.lastname: Fang
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Jia
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Dengkui
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Fan
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Ma
authors.affiliation: Key Laboratory of Physics and Technology for Advanced Batteries, Ministry of Education, College of Physics, JilinUniversity , Changchun 130012, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
authors.affiliation: State Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology , 7089 Wei-Xing Road, Changchun 130022, P. R. China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Wang
keywords: ZnO; core−shell nanowires; electroluminescence; gan; heterojunction; localized excitons