Photoluminescence transient study of surface defects in ZnO nanorods grown by chemical bath deposition
Photoluminescence transient study of surface defects in ZnO nanorods grown by chemical bath deposition
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DOI：
10.1063/1.4914067
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发表时间：
2015-03-02
影响因子：
4
通讯作者：
Mirabella, S.
中科院分区：
文献类型：
--
作者：
Barbagiovanni, E. G.;Strano, V.;Mirabella, S.
在低成本化学浴沉积法制备的ZnO纳米棒中，发现了两个与氧空位（Vo）相关的深度缺陷（2.25 eV和2.03 eV）。发现两种Vo态的光致发光（PL）强度的瞬态行为对环境和NR生长后处理敏感。在热板上干燥的样品中发现了最大的瞬态，仅在空气中，2.25和2.03 eV峰的PL强度衰减时间分别为23和80 s。紫外线照射下的电阻测量显示出与PL瞬态完全一致的瞬态行为，表明大气O-2对表面缺陷状态的明确作用。提出了一种基于费米能级的带弯曲表面缺陷瞬态行为模型。研究结果对ZnO纳米粒子的各种传感和光伏应用具有重要意义。(C) 2015 AIP出版有限责任公司
Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (Vo) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two Vo states was found to be sensitive to the ambient environment and to NR post-growth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient, indicating a clear role of atmospheric O-2 on the surface defect states. A model for surface defect transient behaviour due to band bending with respect to the Fermi level is proposed. The results have implications for a variety of sensing and photovoltaic applications of ZnO NRs. (C) 2015 AIP Publishing LLC.