Dynamics and Mechanisms of Exfoliated Black Phosphorus Sublimation
Dynamics and Mechanisms of Exfoliated Black Phosphorus Sublimation
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DOI：
10.1021/acs.jpclett.6b00584
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发表时间：
2016-05-05
影响因子：
5.7
通讯作者：
Moutanabbir, Oussama
中科院分区：
文献类型：
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作者：
Fortin-Deschenes, Matthieu;Levesque, Pierre L.;Moutanabbir, Oussama
我们报告的真实的时间观察整个退火过程中剥离的黑磷层的升华使用原位低能电子显微镜。我们发现，升华在375 +/-20 ℃以上通过不对称的多面孔的成核和膨胀而表现出来，所述孔的长轴沿沿着[100]方向对齐，并且尖锐的尖端由由交替的（10）和（11）台阶组成的边缘限定。这种热激活过程通过各个层的连续升华来重复。使用密度泛函理论和动力学蒙特卡罗的计算和模拟允许确定所涉及的原子路径。发现升华是通过磷二聚体而不是单个原子的分解发生的。这种行为和缺陷的作用是使用一个分析模型来描述的，该模型捕获了所有基本特征。这项工作建立了剥离黑磷的热稳定性的原子级理解，并定义了材料和器件加工可用的温度窗口。
We report on real time observations of the sublimation of exfoliated black phosphorus layers throughout annealing using in situ low energy electron microscopy. We found that sublimation manifests itself above 375 +/- 20 degrees C through the nucleation and expansion of asymmetric, faceted holes with the long axis aligned along the [100] direction and sharp tips defined by edges consisting of alternating (10) and (11) steps. This thermally activated process repeats itself via successive sublimation of individual layers. Calculations and simulations using density functional theory and kinetic Monte Carlo allowed to determine the involved atomic pathways. Sublimation is found to occur via detachments of phosphorus dimers rather than single atoms. This behavior and the role of defects is described using an analytical model that captures all essential features. This work establishes an atomistic-level understanding of the thermal stability of exfoliated black phosphorus and defines the temperature window available for material and device processing.