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Large‐Scale Horizontally Aligned ZnO Microrod Arrays with Controlled Orientation, Periodic Distribution as Building Blocks for Chip‐in Piezo‐Phototronic LEDs
Author(s) -
Guo Zhen,
Li Haiwen,
Zhou Lianqun,
Zhao Dongxu,
Wu Yihui,
Zhang Zhiqiang,
Zhang Wei,
Li Chuanyu,
Yao Jia
Publication year - 2015
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201402151
Subject(s) - light emitting diode , heterojunction , materials science , optoelectronics , combing , electroluminescence , orientation (vector space) , nanotechnology , optics , layer (electronics) , physics , composite material , geometry , mathematics
A novel method of fabricating large‐scale horizontally aligned ZnO microrod arrays with controlled orientation and periodic distribution via combing technology is introduced. Horizontally aligned ZnO microrod arrays with uniform orientation and periodic distribution can be realized based on the conventional bottom‐up method prepared vertically aligned ZnO microrod matrix via the combing method. When the combing parameters are changed, the orientation of horizontally aligned ZnO microrod arrays can be adjusted (θ = 90° or 45°) in a plane and a misalignment angle of the microrods (0.3° to 2.3°) with low‐growth density can be obtained. To explore the potential applications based on the vertically and horizontally aligned ZnO microrods on p ‐GaN layer, piezo‐phototronic devices such as heterojunction LEDs are built. Electroluminescence (EL) emission patterns can be adjusted for the vertically and horizontally aligned ZnO microrods/ p ‐GaN heterojunction LEDs by applying forward bias. Moreover, the emission color from UV‐blue to yellow‐green can be tuned by investigating the piezoelectric properties of the materials. The EL emission mechanisms of the LEDs are discussed in terms of band diagrams of the heterojunctions and carrier recombination processes.