Raman Spectroscopy, Photocatalytic Degradation, and Stabilization of Atomically Thin Chromium Tri-iodide
Raman Spectroscopy, Photocatalytic Degradation, and Stabilization of Atomically Thin Chromium Tri-iodide
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DOI：
10.1021/acs.nanolett.8b01131
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发表时间：
2018-07-01
期刊：
影响因子：
10.8
通讯作者：
Lau, Chun Ning
中科院分区：
文献类型：
--
作者：
Shcherbakov, Dmitry;Stepanov, Petr;Lau, Chun Ning
作为一种具有磁性有序的二维铁磁半导体，原子薄型三碘化铬是二维(2D)材料家族的最新成员。然而，由于CrI3基器件和异质结构在环境条件下的极端不稳定性，现实的探索是具有挑战性的。在这里，我们给出了CrI3的拉曼表征，并证明了CrI3的主要降解途径是水对碘的光催化取代。虽然用氧化铝、PMMA和六方氮化硼(HBN)进行简单的封装只会适度降低降解率，但最大限度地减少光照可以显著提高稳定性，而且夹在hBN层之间的CrI3片在空气中稳定10天。通过监测CrI_3/石墨烯异质结构在降解过程中的转移特性，我们发现水铬溶液是空穴掺杂石墨烯的。
As a 2D ferromagnetic semiconductor with magnetic ordering, atomically thin chromium tri-iodide is the latest addition to the family of two-dimensional (2D) materials. However, realistic exploration of CrI3-based devices and heterostructures is challenging due to its extreme instability under ambient conditions. Here, we present Raman characterization of CrI3 and demonstrate that the main degradation pathway of CrI3 is the photocatalytic substitution of iodine by water. While simple encapsulation by Al2O3, PMMA, and hexagonal BN (hBN) only leads to modest reduction in degradation rate, minimizing light exposure markedly improves stability, and CrI3 sheets sandwiched between hBN layers are air stable for >10 days. By monitoring the transfer characteristics of the CrI3/graphene heterostructure over the course of degradation, we show that the aquachromium solution hole-dopes graphene.