title: Covalent Nitrogen Doping and Compressive Strain in MoS2 by Remote N2 Plasma Exposure.
abstract: Controllable doping of two-dimensional materials is highly desired for ideal device performance in both hetero- and p-n homojunctions. Herein, we propose an effective strategy for doping of MoS2 with nitrogen through a remote N2 plasma surface treatment. By monitoring the surface chemistry of MoS2 upon N2 plasma exposure using in situ X-ray photoelectron spectroscopy, we identified the presence of covalently bonded nitrogen in MoS2, where substitution of the chalcogen sulfur by nitrogen is determined as the doping mechanism. Furthermore, the electrical characterization demonstrates that p-type doping of MoS2 is achieved by nitrogen doping, which is in agreement with theoretical predictions. Notably, we found that the presence of nitrogen can induce compressive strain in the MoS2 structure, which represents the first evidence of strain induced by substitutional doping in a transition metal dichalcogenide material. Finally, our first principle calculations support the experimental demonstration of such strain, and a correlation between nitrogen doping concentration and compressive strain in MoS2 is elucidated.
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Angelica
authors: A
authors: Azcatl
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Xiaoye
authors: X
authors: Qin
authors: Department of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University , West Lafayette 47907, Indiana United States.
authors: Abhijith
authors: A
authors: Prakash
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Chenxi
authors: C
authors: Zhang
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Lanxia
authors: L
authors: Cheng
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Qingxiao
authors: Q
authors: Wang
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Ning
authors: N
authors: Lu
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Moon J
authors: MJ
authors: Kim
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Jiyoung
authors: J
authors: Kim
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Kyeongjae
authors: K
authors: Cho
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Rafik
authors: R
authors: Addou
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Christopher L
authors: CL
authors: Hinkle
authors: Department of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University , West Lafayette 47907, Indiana United States.
authors: Joerg
authors: J
authors: Appenzeller
authors: Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States.
authors: Robert M
authors: RM
authors: Wallace
keywords: Covalent; MoS2; N2 plasma; p-type doping; strain