Metal-2D multilayered semiconductor junctions: layer-number dependent Fermi-level pinning

Wang, Qian1,2; Shao, Yangfan1,3; Gong, Penglai1; Shi, Xingqiang1

2020

10.1039/c9tc06331e

Journal of Materials Chemistry C   影响因子和分区

20507526

2050-7534

The thickness-dependent performances of metal-two-dimensional (2D) semiconductor junctions in electronics/optoelectronics have attracted increasing attention but, currently, little knowledge about the micro-mechanism of this thickness (or layer-number) dependence is available. Here, by first-principles calculations based on density functional theory, we show that the Fermi-level pinning (FLP) factor of a metal-2D multilayered semiconductor junction (MmSJ) has a sensitive dependence on the layer-number of the MmSJ for few-layer 2D semiconductors, in a proposed extension of FLP theory. Taking a MmSJ with MoS2 as a typical example, we find that strong pinning arises right at the metal-1st-layer semiconductor interface, while depinning occurs between the MoS2 layers. The depinning effect mainly contributes to the variation of the FLP factor as a function of the layer-number of the semiconductor, making p-type Schottky barrier contact more favorable in MmSJs than in metal-2D monolayer semiconductor junctions, especially for large work-function metals. Moreover, our results shed light on recent controversial experimental observations relating to MmSJs and metal-2D monolayer semiconductor junctions.
This journal is © 2020 The Royal Society of Chemistry.

EI ; SCI

英语

第一

Natural Science Foundation of Guangdong Province[2017A030310661] ; [2019B030301001] ; [JCYJ20170817105007999]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied

WOS:000519972600019

Royal Society of Chemistry

20201208306732

Calculations ; Density functional theory ; Fermi level ; Layered semiconductors ; Metals ; Molybdenum compounds ; Monolayers ; Schottky barrier diodes

Semiconductor Devices and Integrated Circuits:714.2 ; Mathematics:921 ; Atomic and Molecular Physics:931.3

EV Compendex

1.Department of Physics and Guangdong Provincial, Key Laboratory for Computational Science and Material Design, Southern University of Science and Technology, Shenzhen; 518055, China
2.Harbin Institute of Technology, Harbin; 150080, China
3.Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, China

Wang, Qian,Shao, Yangfan,Gong, Penglai,et al. Metal-2D multilayered semiconductor junctions: layer-number dependent Fermi-level pinning[J]. Journal of Materials Chemistry C,2020,8(9):3113-3119.

Wang, Qian,Shao, Yangfan,Gong, Penglai,&Shi, Xingqiang.(2020).Metal-2D multilayered semiconductor junctions: layer-number dependent Fermi-level pinning.Journal of Materials Chemistry C,8(9),3113-3119.

Wang, Qian,et al."Metal-2D multilayered semiconductor junctions: layer-number dependent Fermi-level pinning".Journal of Materials Chemistry C 8.9(2020):3113-3119.