Controlled Synthesis of Ultrathin PtSe2 Nanosheets with Thickness‐Tunable Electrical and Magnetoelectrical Properties

Advanced Science

Biao Qin¹  Bo Li¹  Qi Qian²  Zhong Wan²  Jia Li³  Zucheng Zhang³  Hongmei Zhang³  Xidong Duan³  Bei Zhao³  Huifang Ma³  Ruixia Wu³  Zhengwei Zhang³  Lin Wang⁴ 

[1]Department of Applied Physics School of Physics and Electronics Hunan University Changsha 410082 China

[2]Department of Chemistry and Biochemistry University of California Los Angeles California 90095 United States

[3]Hunan Key Laboratory of Two‐Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University Changsha 410082 China

[4]Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211800 China

关键词: 2D materials;    carrier mobility;    chemical vapor deposition;    Kondo effect;    negative magnetoresistance;   

DOI  :  10.1002/advs.202103507

来源: DOAJ

【 摘 要 】

Abstract Thickness‐dependent chemical and physical properties have gained tremendous interest since the emergence of two‐dimensional (2D) materials. Despite attractive prospects, the thickness‐controlled synthesis of ultrathin nanosheets remains an outstanding challenge. Here, a chemical vapor deposition (CVD) route is reported to controllably synthesize high‐quality PtSe2 nanosheets with tunable thickness and explore their thickness‐dependent electronic and magnetotransport properties. Raman spectroscopic studies demonstrate all Eg, A1g, A2u, and Eu modes are red shift in thicker nanosheets. Electrical measurements demonstrate the 1.7 nm thick nanosheet is a semiconductor with room temperature field‐effect mobility of 66 cm2 V−1 s−1 and on/off ratio of 106. The 2.3–3.8 nm thick nanosheets show slightly gated modulation with high field‐effect mobility up to 324 cm2 V−1 s−1 at room‐temperature. When the thickness is over 3.8 nm, the nanosheets show metallic behavior with conductivity and breakdown current density up to 6.8 × 105 S m–1 and 6.9 × 107 A cm−2, respectively. Interestingly, magnetoresistance (MR) studies reveal magnetic orders exist in this intrinsically non‐magnetic material system, as manifested by the thickness‐dependent Kondo effect, where both metal to insulator transition and negative MR appear upon cooling. Together, these studies suggest that PtSe2 is an intriguing system for both developing novel functional electronics and conducting fundamental 2D magnetism study.

【 授权许可】

Unknown