Murphy M W, Zhou X T, Ko J Y P, Zhou J G, Heigl F, Sham T K
Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7, Canada.
J Chem Phys. 2009 Feb 28;130(8):084707. doi: 10.1063/1.3080767.
The electronic structure and optical properties of biaxial ZnO-ZnS heterostructure nanoribbons (NRs) have been investigated using x-ray absorption near-edge structures (XANES) and x-ray excited optical luminescence (XEOL). The XANES were recorded in total electron yield and wavelength-selected photoluminescence yield across the K- and L(3,2)-edges of zinc and sulfur and the K-edge of oxygen. The XEOL from the NRs exhibit a very weak band-gap emission at 392 nm and two intense defect emissions at 491 and 531 nm. The synchrotron x-ray pulse ( approximately 100 ps, 153 ns repetition rate) was used to track the optical decay dynamics from ZnO-ZnS NR, which can be described by two lifetimes (7.6 and 55 ns). Comparison with similar measurements for ZnO and ZnS nanowires reveals that the luminescence from ZnO-ZnS NRs was dominated by the ZnO component of the NR as the ZnS component contributes little. The implication of this observation is discussed.
利用X射线吸收近边结构（XANES）和X射线激发光致发光（XEOL）研究了双轴ZnO-ZnS异质结构纳米带（NRs）的电子结构和光学性质。在锌和硫的K边和L(3,2)边以及氧的K边，通过总电子产率和波长选择光致发光产率记录了XANES。NRs的XEOL在392nm处表现出非常微弱的带隙发射，在491和531nm处表现出两个强烈的缺陷发射。同步加速器X射线脉冲（约100ps，153ns重复率）用于跟踪ZnO-ZnS NR的光学衰减动力学，其可以用两个寿命（7.6和55ns）来描述。与ZnO和ZnS纳米线的类似测量结果比较表明，ZnO-ZnS NRs的发光主要由NR的ZnO成分主导，因为ZnS成分贡献很小。讨论了这一观察结果的意义。
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