Photoabsorption Tolerance of Intrinsic Point Defects and Oxidation in Black Phosphorus Quantum Dots
Photoabsorption Tolerance of Intrinsic Point Defects and Oxidation in Black Phosphorus Quantum Dots
复制标题
黑磷量子点本征点缺陷和氧化的光吸收耐受性
DOI：
10.1021/acs.jpclett.6b02486
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发表时间：
2017
影响因子：
5.7
通讯作者：
Wang Jinlan
中科院分区：
文献类型：
--
作者：
Niu Xianghong;Shu Huabing;Li Yunhai;Wang Jinlan
黑磷量子点具有优异的光学和光热性能，在光电子学和生物医学等领域具有广阔的应用前景。然而，在BPQD的制备过程中，各种本征结构缺陷和氧化几乎是不可避免的，它们是如何影响BPQD的电子和光学性质的，目前还不清楚。在这里，我们利用含时密度泛函理论，揭示了BPQD中存在点缺陷和氧化两种类型的光吸收。揭示了一种密切的结构-吸收关系：当缺陷P原子的配位数(Cn)为3时，≠量子点具有较好的光吸收性能，而不饱和或过饱和的P原子与Cn BPQD原子形成In-Gap态(IGS)并完全猝灭光吸收.进一步提出了通过充分的氢钝化来消除IGS和修复缺陷BPQD光吸收的有效方法。
Black phosphorus quantum dots (BPQDs) exhibit excellent optical and photothermal properties and promising applications in optoelectronics and biomedicine. However, various intrinsic structural defects and oxidation are nearly unavoidable in preparation of BPQDs and how they affect the electronic and optical properties remains unclear. Here, by employing time-dependent density functional theory, we reveal that there are two types of photoabsorption in BPQDs for both point defects and oxidation. A close structure-absorption relation is unraveled: BPQDs are defect-tolerant and show excellent photoabsorption as long as the coordination number (CN) of defective P atoms is 3. By contrast, the unsaturated or oversaturated P atoms with CN ≠ 3 create in-gap-states (IGSs) and completely quench the optical absorption. An effective way to eliminate the IGSs and repair the photoabsorption of defective BPQDs via sufficient hydrogen passivation is further proposed.