Photoluminescence enhancement of ZnO nanowire arrays by atomic layer deposition of ZrO2 layers and thermal annealing
Photoluminescence enhancement of ZnO nanowire arrays by atomic layer deposition of ZrO2 layers and thermal annealing
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通过 ZrO2 层原子层沉积和热退火增强 ZnO 纳米线阵列的光致发光
DOI：
10.1039/c6cp01900e
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发表时间：
2016
影响因子：
3.3
通讯作者：
Zhang David Wei
中科院分区：
文献类型：
--
作者：
Zhang Yuan;Lu Hong-Liang;Wang Tao;Ren Qing-Hua;Chen Hong-Yan;Zhang Hao;Ji Xin-Ming;Liu Wen-Jun;Ding Shi-Jin;Zhang David Wei
研究了壳层厚度和快速热退火对一维ZnO/ZrO 2核/壳纳米线光致发光特性的影响。采用原子层沉积法在ZnO纳米线表面包覆一层ZrO 2薄膜，制备了ZnO/ZrO 2核壳结构纳米线。形貌和结构表征研究表明，ZrO 2壳层具有多晶结构，均匀且共形地包覆在高质量的单晶ZnO纳米线上。与裸ZnO纳米线相比，ZnO/ZrO 2核/壳结构的紫外发射强度随着ZrO 2壳层厚度的增加而不断增强，最大可达10 nm。紫外发射的显著改善机制来自于I型核/壳系统的表面钝化和有效的载流子限制效应。此外，它是观察到的ZnO/ZrO 2核/壳结构的热退火后的UV发射随退火温度的增加而增加。裸ZnO纳米线和ZnO/ZrO 2核/壳纳米结构中的主要表面激子（SX）发射已被检测到在低温光致发光光谱。在ZnO纳米线中，随着ZrO 2壳层的生长和进一步的热处理，NBE发射峰的蓝移以及SX发射强度的衰减速率也发生了变化。我们的研究结果表明，ZnO/ZrO 2核/壳纳米结构可以广泛地应用于未来的光学和电子器件。
The effects of shell thickness and rapid thermal annealing on photoluminescence properties of one-dimensional ZnO/ZrO2 core/shell nanowires (NWs) are studied in this work. The ZnO/ZrO2 core/shell structures were synthesized by coating thin ZrO2 layers on the surface of ZnO NWs using atomic layer deposition. The morphological and structural characterization studies reveal that the ZrO2 shells have a polycrystalline structure, which are uniformly and conformally coated on the high quality single-crystal ZnO NWs. As compared with bare ZnO NWs, the ZnO/ZrO2 core/shell structures show a remarkable and continuous enhancement of ultraviolet (UV) emission in intensity with increasing ZrO2 shell thickness up to 10 nm. The great improvement mechanism of the UV emission arises from the surface passivation and the efficient carrier confinement effect of the type-I core/shell system. Moreover, it is observed that the UV emission of ZnO/ZrO2 core/shell structures after thermal annealing increases with increasing annealing temperature. The dominant surface exciton (SX) emission in the bare ZnO NWs and the ZnO/ZrO2 core/shell nanostructures has been detected in the low temperature photoluminescence spectra. A blue shift of the NBE emission peak as well as the varied decay rate of the SX emission intensity are also found in the ZnO NWs after the growth of ZrO2 shells and further thermal treatment. Our results suggest that the ZnO/ZrO2 core/shell nanostructures could be widely implemented in the optical and electronic devices in the future.