Identification of Lattice Oxygen in Few-Layer Black Phosphorous Exfoliated in Ultrahigh Vacuum and Largely Improved Ambipolar Field-Effect Mobilities by Hydrogenation and Phosphorization
Identification of Lattice Oxygen in Few-Layer Black Phosphorous Exfoliated in Ultrahigh Vacuum and Largely Improved Ambipolar Field-Effect Mobilities by Hydrogenation and Phosphorization
复制标题
超高真空剥离的少层黑磷中晶格氧的识别以及通过氢化和磷化大大提高的双极场效应迁移率
DOI：
10.1021/acsami.7b12469
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发表时间：
2017
影响因子：
9.5
通讯作者：
Wu X.
中科院分区：
文献类型：
--
作者：
Gui Q.;Zhu X.;Liu L.;Jia Z.-Y.;Song Y.-H.;Li S.-C.;Chu P.K.;Wu X.
黑磷（BP）由于其独特的结构、优异的光学和电学性质以及在光热剂中的应用前景，近年来引起了人们的广泛关注。然而，其主要缺点是在H2O和O2的周围环境中快速降解，这导致了对其稳定性的改进的大量研究。不幸的是，这项研究并没有显示出载流子迁移率的巨大改善。在这里，我们进行扫描隧道显微镜观察的几层BP（FLBP）片剥离在真空中，并揭示，第一次，在晶体生长过程中引入的晶格氧的存在。作为概念验证应用，进行氢化以去除晶格氧原子，然后进行磷化，其修复由机械剥离和氢化引起的磷空位。在2K时，FLBP薄膜的空穴和电子的双极场效应迁移率分别为1374 cm ~ 2 V ~（-1）s ~（-1）和607 cm ~ 2 V ~（-1）s ~（-1）。在空气中储存3天后，空穴和电子迁移率仅分别降低至1181和518 cm 2 V-1 s-1，并且没有观察到结构退化。这项工作提出了一种有效的手段，以提高流动性和稳定性的BP片呈现实际应用的FLBP片可能。
Black phosphorus (BP) has recently attracted considerable attention due to its unique structure and fascinating optical and electronic properties as well as possible applications in photothermal agents. However, its main drawback is rapid degradation in ambient environments of H2O and O2, which has led to much research on the improvement of its stability. Unfortunately, this research has not shown great improvement in carrier mobilities. Here, we perform scanning tunneling microscopy observations of few-layer BP (FLBP) sheets exfoliated in ultrahigh vacuum and reveal, for the first time, the existence of lattice oxygen introduced during crystal growth. As a proof-of-concept application, hydrogenation is conducted to remove the lattice oxygen atoms followed by phosphorization, which repairs the phosphorous vacancies caused by mechanical exfoliation and hydrogenation. The resulting FLBP sheets show high ambipolar field-effect mobilities of 1374 cm2V–1s–1for holes and 607 cm2V–1s–1for electrons at 2 K. After storage in air for 3 days, the hole and electron mobilities only decrease to 1181 and 518 cm2V–1s–1, respectively, and no structural degradation is observed. This work suggests an effective means to improve both the mobility and stability of BP sheets rendering practical application of FLBP sheets possible.