Growth and optical properties of ZnO nanostructures by vapor transport process
Growth and optical properties of ZnO nanostructures by vapor transport process
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DOI：
10.1016/j.matchemphys.2007.02.015
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发表时间：
2007-05
影响因子：
4.6
通讯作者：
Y. Tong;Y. Liu;Lin Dong;L. X. Lu;Duan Zhao;J. Zhang;Y. Lu;D. Shen;X. Fan
中科院分区：
文献类型：
--
作者：
Y. Tong;Y. Liu;Lin Dong;L. X. Lu;Duan Zhao;J. Zhang;Y. Lu;D. Shen;X. Fan
采用热蒸发法制备了氧化锌纳米棒和氧化锌纳米管。在位于Zn源上方的ITO衬底上得到的ZnO纳米棒直径不均匀，中间发生突变，这可能是由于体系中Zn蒸气的减少所致。在上游区域得到了表面粗糙的ZnO纳米管。在ZnO纳米管中可以观察到光致发光的负热猝灭现象。这与大量的表面/界面缺陷有关，这些缺陷会在带隙中引入大量的中间态。根据Shibata的模型，通过拟合紫外光致发光强度温度依赖性的实验数据，可以得到电子从中间态到初始态的活化能。拟合能量值高达~ 100meV，这可能是在163.5 ~ 205.6K高温范围内负热猝灭的原因。
ZnO nanorods and ZnO nanotubes have been fabricated by thermally evaporating the metal Zn powder. The ZnO nanorod obtained on the ITO substrate located above the Zn source has the uneven diameter with the abrupt change in its middle, which may originate from the decrease of the Zn vapor in the system. The ZnO nanotubes with the rough surfaces were obtained in the upstream region. The negative thermal quenching of the photoluminescence can be observed in the ZnO nanotubes. This is related with the abundant surface/interface defects which can introduce a large number of middle states in the band gap. According to Shibata's model, the activation energy of the electrons from the middle states to the initial states can be obtained by fitting the experimental data of the temperature dependence of the ultraviolet photoluminescence intensity. The fitting energy values are as high as ∼100meV, which may be responsible for the negative thermal quenching in a high-temperature range from 163.5 to 205.6K.