Formation of low-resistance metal contacts is the biggest challenge that masks the intrinsic exceptional electronic properties of 2D WSe2 devices. We present the first comparative study of the interfacial properties between ML/BL WSe2 and Sc, Al, Ag, Au, Pd, and Pt contacts by using ab initio energy band calculations with inclusion of the spin-orbital coupling (SOC) effects and quantum transport simulations. The interlayer coupling tends to reduce both the electron and hole Schottky barrier heights (SBHs) and alters the polarity for WSe2-Au contact, while the SOC chiefly reduces the hole SBH. In the absence of the SOC, Pd contact has the smallest hole SBH with a value no less than 0.22 eV. Dramatically, Pt contact surpasses Pd contact and becomes p-type Ohmic or quasi-Ohmic contact with inclusion of the SOC. Our study provides a theoretical foundation for the selection of favorable metal electrodes in ML/BL WSe2 devices.
@article{arxiv.1508.00300,
title = {Does P-type Ohmic Contact Exist in WSe2-metal Interfaces?},
author = {Yangyang Wang and Ruoxi Yang and Ruge Quhe and Hongxia Zhong and Linxiao Cong and Meng Ye and Zeyuan Ni and Zhigang Song and Jinbo Yang and Junjie Shi and Ju Li and Jing Lu},
journal= {arXiv preprint arXiv:1508.00300},
year = {2016}
}