Understanding Photoluminescence of Monodispersed Crystalline Anatase TiO2 Nanotube Arrays
Understanding Photoluminescence of Monodispersed Crystalline Anatase TiO2 Nanotube Arrays
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DOI：
10.1021/jp4125588
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发表时间：
2014-04
影响因子：
3.7
通讯作者：
Hyunjun Yoo;Myungjun Kim;Changdeuck Bae;Seonhee Lee;Hyunchul Kim;T. Ahn;Hyunjung Shin
中科院分区：
文献类型：
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作者：
Hyunjun Yoo;Myungjun Kim;Changdeuck Bae;Seonhee Lee;Hyunchul Kim;T. Ahn;Hyunjung Shin
尽管纳米结构TiO2在许多应用中具有巨大的潜力，但迄今为止，对其缺陷结构相关的光学性质的具体理解仍然难以捉摸。在这里，我们系统地研究了锐钛矿型TiO2纳米管（TNT）阵列的光致发光（PL）特性与壁厚（wall）和晶粒尺寸的关系。采用模板定向原子层沉积技术制备高度均匀的锐钛矿型tnt，然后进行热退火。利用非晶向锐钛矿转变过程中厚壁层和薄壁层之间的结晶动力学，以可控的方式调整了表面/晶界（GB）缺陷与大块氧空位的相对数量。在300 ~ 20 K的不同温度下，获得了锐钛矿TNT阵列的PL光谱。值得注意的是，通过改变壁，可以从自捕获激子、氧空位或表面/GB缺陷中识别出主要的PL发射。我们的结果表明……
Despite huge potential of nanostructured TiO2 in many applications, the concrete understanding of optical properties associated with their defect structures remains elusive to date. Here, we present a systematic study on the photoluminescence (PL) characteristics of anatase TiO2 nanotube (TNT) arrays as a function of wall thicknesses (twall) and thereby grain sizes. Highly uniform anatase TNTs were prepared by template-directed atomic layer deposition techniques, followed by thermal annealing. The relative amounts of surface/grain boundary (GB) defects to the bulk oxygen vacancies were tailored in a controlled manner by utilizing the crystallization kinetics between thin and thick wall layers during amorphous to anatase transformation. PL spectra of anatase TNT arrays were attained at variable temperatures from 300 down to 20 K. By changing twall, remarkably, the predominant PL emissions were likely discernible from either self-trapped excitons, oxygen vacancies, or surface/GB defects. Our results indicat...