Realization of In-Plane p-n Junctions with Continuous Lattice of a Homogeneous Material.

Huang, Xiaochun; Liu, Bing; Guan, Jiaqi; Miao, Guangyao; Lin, Zijian; An, Qichang; Zhu, Xuetao; Wang, Weihua et al. · Adv Mater · 2018

basic_science · Level V

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Abstract

Two-dimensional (2D) in-plane p-n junctions with a continuous interface have great potential in next-generation devices. To date, the general fabrication strategies rely on lateral epitaxial growth of p- and n-type 2D semiconductors. An in-plane p-n junction is fabricated with homogeneous monolayer Te at the step edge on graphene/6H-SiC(0001). Scanning tunneling spectroscopy reveals that Te on the terrace of trilayer graphene is p-type, and it is n-type on monolayer graphene. Atomic-resolution images demonstrate the continuous lattice of the junction, and mappings of the electronic states visualize the type-II band bending across the space-charge region of 6.2 nm with a build-in field of 4 × 10<sup>5</sup> V cm<sup>-1</sup> . The reported strategy can be extended to other 2D semiconductors on patternable substrates for designed fabrication of in-plane junctions.