Galdámez-Martinez Andres, Santana Guillermo, Güell Frank, Martínez-Alanis Paulina R, Dutt Ateet
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Coyoacan, México City 04510, Mexico.
ENFOCAT-IN2UB, Universitat de Barcelona, C/Martí i Franquès 1, 08028 Barcelona, Catalunya, Spain.
Nanomaterials (Basel). 2020 Apr 29;10(5):857. doi: 10.3390/nano10050857.
One-dimensional ZnO nanostructures (nanowires/nanorods) are attractive materials for applications such as gas sensors, biosensors, solar cells, and photocatalysts. This is due to the relatively easy production process of these kinds of nanostructures with excellent charge carrier transport properties and high crystalline quality. In this work, we review the photoluminescence (PL) properties of single and collective ZnO nanowires and nanorods. As different growth techniques were obtained for the presented samples, a brief review of two popular growth methods, vapor-liquid-solid (VLS) and hydrothermal, is shown. Then, a discussion of the emission process and characteristics of the near-band edge excitonic emission (NBE) and deep-level emission (DLE) bands is presented. Their respective contribution to the total emission of the nanostructure is discussed using the spatial information distribution obtained by scanning transmission electron microscopy-cathodoluminescence (STEM-CL) measurements. Also, the influence of surface effects on the photoluminescence of ZnO nanowires, as well as the temperature dependence, is briefly discussed for both ultraviolet and visible emissions. Finally, we present a discussion of the size reduction effects of the two main photoluminescent bands of ZnO. For a wide emission (near ultra-violet and visible), which has sometimes been attributed to different origins, we present a summary of the different native point defects or trap centers in ZnO as a cause for the different deep-level emission bands.
一维氧化锌纳米结构（纳米线/纳米棒）是用于气体传感器、生物传感器、太阳能电池和光催化剂等应用的有吸引力的材料。这是由于这类纳米结构的制备过程相对简单，具有优异的电荷载流子传输特性和高结晶质量。在这项工作中，我们综述了单个和集体氧化锌纳米线及纳米棒的光致发光（PL）特性。由于所呈现的样品采用了不同的生长技术，因此简要介绍了两种常用的生长方法，即气-液-固（VLS）法和水热法。然后，讨论了近带边激子发射（NBE）和深能级发射（DLE）带的发射过程及特性。利用扫描透射电子显微镜-阴极发光（STEM-CL）测量获得的空间信息分布，讨论了它们对纳米结构总发射的各自贡献。此外，还简要讨论了表面效应以及温度依赖性对氧化锌纳米线紫外和可见光发射光致发光的影响。最后，我们讨论了氧化锌两个主要光致发光带的尺寸减小效应。对于有时归因于不同起源的宽发射（近紫外和可见光），我们总结了氧化锌中不同的本征点缺陷或陷阱中心，作为不同深能级发射带的原因。
