Chemical Vapor Deposition Grown Wafer-Scale 2D Tantalum Diselenide with Robust Charge-Density-Wave Order
Chemical Vapor Deposition Grown Wafer-Scale 2D Tantalum Diselenide with Robust Charge-Density-Wave Order
复制标题
具有鲁棒电荷密度波序的化学气相沉积生长晶圆级二维二硒化钽
DOI：
10.1002/adma.201804616
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发表时间：
2018
影响因子：
29.4
通讯作者：
Deng
中科院分区：
文献类型：
--
作者：
Shi Jianping;Zhao Liyun;Hong Min;Huan Yahuan;Zhang Zhepeng;Yang Pengfei;Zhang Qing;Zhang Yanfeng;Shi Jianping;Hong Min;Huan Yahuan;Zhang Zhepeng;Yang Pengfei;Zhang Yanfeng;Shi Jianping;Wang Jian;Shi Jianping;Gu Lin;Wang Jian;Chen Xuexian;Chen Huanjun;Deng
二维金属过渡金属二硫族化物（MTMDCs）是揭示量子物理中维数效应的基准体系，如电荷-密度-波（CDW）秩序、非常规超导性和磁性等。然而，这种设想的MTMDCs的可扩展和厚度可调的合成仍然具有挑战性。同时，二维极限下CDW顺序的起源存在争议。本文采用化学气相沉积法在金箔上直接合成了晶圆级均匀单层2H - tase2薄膜和厚度可调薄片。基于厚度可调的2H - TaSe2，通过低温透射电子显微镜直接观察到与CDW序相关的鲁棒周期性晶格畸变。特别地，通过变温拉曼表征建立了从普通金属相到CDW相随厚度转变温度的相图。有趣的是，从单层2H‐TaSe2中观察到从体值≈90到≈125 K的转变温度显著提高，这可以用增强的电子-声子耦合机制来解释。更重要的是，在碳布上生长的tase2作为超级电容器电极也获得了超高的比电容。这一结果为大规模制备高质量的MTMDCs开辟了新的途径，并为其在探索一些基本问题上的应用提供了新的思路。
2D metallic transition metal dichalcogenides (MTMDCs) are benchmark systems for uncovering the dimensionality effect on fascinating quantum physics, such as charge‐density‐wave (CDW) order, unconventional superconductivity, and magnetism, etc. However, the scalable and thickness‐tunable syntheses of such envisioned MTMDCs are still challenging. Meanwhile, the origin of CDW order at the 2D limit is controversial. Herein, the direct synthesis of wafer‐scale uniform monolayer 2H‐TaSe2films and thickness‐tunable flakes on Au foils by chemical vapor deposition is accomplished. Based on the thickness‐tunable 2H‐TaSe2, the robust periodic lattice distortions that relate to CDW orders by low‐temperature transmission electron microscopy are directly visualized. Particularly, a phase diagram of the transition temperature from normal metallic to CDW phases with thickness by variable‐temperature Raman characterizations is established. Intriguingly, dramatically enhanced transition temperature from bulk value ≈90 to ≈125 K is observed from monolayer 2H‐TaSe2, which can be explained by the enhanced electron–phonon coupling mechanism. More importantly, an ultrahigh specific capacitance is also obtained for the as‐grown TaSe2on carbon cloth as supercapacitor electrodes. The results hereby open up novel avenues toward the large‐scale preparation of high‐quality MTMDCs, and shed light on their applications in exploring some fundamental issues.