The role of adsorbates in the green emission and conductivity of zinc oxide
The role of adsorbates in the green emission and conductivity of zinc oxide
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DOI：
10.1038/s42004-019-0153-0
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发表时间：
2019-05-02
影响因子：
5.9
通讯作者：
Konezny, Steven J.
中科院分区：
文献类型：
--
作者：
Rohr, Jason A.;Sa, Jacinto;Konezny, Steven J.
氧化锌是一种多功能半导体，具有广泛的应用范围，包括照明、传感和太阳能转换。与其性能相关的两个核心现象仍在深入研究中，即其子带隙绿光发射的起源及其电导率的性质。我们报告了各种大气条件下氧化锌纳米粒子薄膜的光致发光和暗电导率测量，证明了吸附物的重要作用。我们表明，通过促进从导带提供或提取电子的物质的吸附，可以可逆地调节紫外线发射和电导率。当将电导率数据与在相同环境条件下获取的光致发光光谱进行比较时，绿色发射可以直接与表面超氧化物的形成相关，而不是与表面羟基化或氧空位等天然缺陷相关。这证明并解释了为什么绿色排放可以通过表面反应性和化学环境来控制。
Zinc oxide is a versatile semiconductor with an expansive range of applications including lighting, sensing and solar energy conversion. Two central phenomena coupled to its performance that remain heavily investigated are the origin of its sub-band-gap green emission and the nature of its conductivity. We report photoluminescence and dark conductivity measurements of zinc oxide nanoparticle films under various atmospheric conditions that demonstrate the vital role of adsorbates. We show that the UV emission and conductivity can be tuned reversibly by facilitating the adsorption of species that either donate or extract electrons from the conduction band. When the conductivity data are compared with photoluminescence spectra taken under the same ambient conditions, the green emission can be directly linked to surface superoxide formation, rather than surface hydroxylation or native defects such as oxygen vacancies. This demonstrates how and explains why the green emission can be controlled by surface reactivity and chemical environment.