State Key Laboratory of Optoelectronic Materials and Technologies, Institute of Optoelectronic and Functional Composite Materials, Nanotechnology Research Center, School of Materials Science & Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Nanoscale. 2016 Apr 28;8(17):9226-33. doi: 10.1039/c6nr00911e.
Hollow ZnO microcolumns with size induced photoluminescence and cathodoluminescence properties were prepared by a thermal chemical vapor transport and condensation method. It was found that the luminescence emission could be confined in the nano-sized hollow core and the wavelength dependent light intensity could be influenced by the geometric structure of the ZnO microcolumn, which can act as a hollow optical waveguide. Based on the antiresonant reflection in the optical waveguide, we established a theoretical model to address the field enhancement in the hollow ZnO microcolumn, which systematically clarifies the influence of the geometric structure of the microcolumn on the field enhancement. We report for the first time, the enhanced emission of the near ultraviolet light (working wavelength of 385 nm) along the axial direction of the ZnO microcolumn. The corresponding microsized light emitter has also been obtained. Experiments agree well with both theoretical predictions and computer simulations based on the finite-difference time-domain method with perfectly matched layer boundary conditions. These findings provide valuable information for the application of ZnO micro- and nanostructures in optoelectronic devices.
采用热化学气相输运和冷凝法制备了具有尺寸诱导光致发光和阴极发光性能的中空 ZnO 微柱。研究发现，发光发射可以限制在纳米级的中空核心内，并且波长相关的光强度可以受到 ZnO 微柱的几何结构的影响，从而可以作为中空光学波导。基于光学波导中的反共振反射，我们建立了一个理论模型来解决中空 ZnO 微柱中的场增强问题，该模型系统地阐明了微柱的几何结构对场增强的影响。我们首次报道了沿 ZnO 微柱轴向的近紫外光（工作波长为 385nm）的增强发射。还获得了相应的微尺寸发光体。实验结果与基于完全匹配层边界条件的有限差分时域法的理论预测和计算机模拟吻合得很好。这些发现为 ZnO 微纳结构在光电设备中的应用提供了有价值的信息。
