Surface & Interface Modeling
for Emerging Nanomaterials and Devices

Electrical contacts to monolayer black phosphorus: A first-principles investigation

Kui Gong,1,2 Lei Zhang,2 Wei Ji,3 and Hong Guo2

1School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083 China

2Centre for the Physics of Materials and Department of Physics, McGill University, Montreal, PQ, Canada, H3A 2T8

3Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China

DOI:10.1103/PhysRevB.90.125441    Publication Date: 23 September 2014


We report first-principles theoretical investigations of possible metal contacts to monolayer black phosphorus (BP). By analyzing lattice geometry, five metal surfaces are found to have minimal lattice mismatch with BP: Cu(111), Zn(0001), In(110), Ta(110), and Nb(110). Further studies indicate Ta and Nb bond strongly with monolayer BP causing substantial bond distortions, but the combined Ta-BP and Nb-BP form good metal surfaces to contact a second layer BP. By analyzing the geometry, bonding, electronic structure, charge transfer, potential, and band bending, it is concluded that Cu(111) is the best candidate to form excellent Ohmic contact to monolayer BP. The other four metal surfaces or combined surfaces also provide viable structures to form metal/BP contacts, but they have Schottky character. Finally, the band bending property in the current-in-plane (CIP) structure where metal/BP is connected to a freestanding monolayer BP, is investigated. By both work function estimates and direct calculations of the two-probe CIP structure, we find that the freestanding BP channel is n type.


View: Phys. Rev. B  90, 125441 (2014)     arXiv:1404.7207     Local Copy

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