Anisotropic interfacial properties of monolayer C2N field effect transistors. Issue 48 (8th December 2020)

• Record Type: Journal Article
• Authors: Dong, Mi-Mi; Zhang, Guang-Ping; Li, Zong-Liang; Wang, Ming-Lang; Wang, Chuan-Kui; Fu, Xiao-Xiao
• Is Part Of: Physical chemistry chemical physics. Volume 22:Issue 48(2020)
• Page Start: 28074
• Page End: 28085
• Publication Date: 2020-12-08
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d0cp04450d
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Monolayer C2 N is promising for next-generation electronic and optoelectronic applications due to its appropriate band gap and high carrier efficiency. Abstract : Monolayer C2 N is promising for next-generation electronic and optoelectronic applications due to its appropriate band gap and high carrier efficiency. However, relative studies have been held back due to the lack of high-quality electrode contacts. Here, we comprehensively study the electronic and transport properties of monolayer C2 N with a series of electrode materials (Al, Ti, Ni, Cu, Ag, Pt, V2 C, Cr2 C and graphene) by using the nonequilibrium Green's function (NEGF) method combined with density functional theory (DFT). The monolayer C2 N forms Ohmic contacts with the Ti/Cu/Ag electrode material in both armchair and zigzag directions, whereas Ohmic contact is only formed in the zigzag direction of the C2 N–Al field effect transistor. However, the C2 N–Ni, –Pt, –V2 C, –Mo2 C, –graphene contact systems form n-type Schottky contacts in either the armchair or zigzag direction owing to the relatively strong Fermi level pinning (the pinning factor S = 0.32 in the armchair direction and S = 0.26 in the zigzag direction). By insertion of BN or graphene between the C2 N and Pt electrode in the armchair direction of contact systems, the Fermi level pinning can be effectively weakened due to the suppression of metal-induced gap states. Conspicuously, an Ohmic contact is realized in the C2 N field effect transistors with the BN–Pt electrode, suggesting a possible approach to fabricating high-performance devices. Our study is conducive to selecting appropriate electrode materials for C2 N-based field effect transistors.