title: Bandgap engineering and manipulating electronic and optical properties of ZnO nanowires by uniaxial strain.
abstract: Bandgap engineering is a common practice for tuning semiconductors for desired physical properties. Although possible strain effects in semiconductors have been investigated for over a half-century, a profound understanding of their influence on energy bands, especially for large elastic strain remains unclear. In this study, a systematic investigation of the transport properties of n-type [0001] ZnO nanowires was performed at room temperature using the in situ scanning tunnelling microscope-transmission electron microscope technique which shows that the transport properties vary with the applied external uniaxial strain. It has been found that the resistance of ZnO nanowires decreases continuously with increasing compressive strain, but increases under increased tensile strain, suggesting piezo-resistive characteristics. A series of near-band-edge emissions were measured and the corresponding variations of bandgaps were obtained during the application of tensile strain of individual ZnO nanowires via cathodoluminescence spectroscopy. From this, a relationship between the changes of energy bandgap and the transport properties, both induced by uniaxial strain, is built.
authors.affiliation: Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China. kunzheng@bjut.edu.cn.
authors.forename: Rui-wen
authors.initials: RW
authors.lastname: Shao
authors.forename: Kun
authors.initials: K
authors.lastname: Zheng
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.forename: Yue-fei
authors.initials: YF
authors.lastname: Zhang
authors.forename: Yu-jie
authors.initials: YJ
authors.lastname: Li
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Han
authors.forename: Ze
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Zou