Tunable diodes made by atomically thin lateral heterojunction

• Published in: Science China materials 2023-11, Vol.66 (11), p.4419-4426
• Main Authors: Lu, Xiangchao, Wang, Wei, Zhu, Huijie, Wu, Yongsen, Lu, Yizhen, Shao, Gonglei, Liu, Song, Cao, Yang
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition; Chemistry and Materials Science; Chemistry/Food Science; Crystal lattices; Current carriers; Diodes; Electric contacts; Electronic circuits; Heterojunctions; Heterostructures; Lattice parameters; Materials Science; Molybdenum disulfide; Two dimensional materials
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-023-2586-9

A diode is a fundamental electronic device with rectification characteristics and controls the flow of current in one direction. Atomically thin diodes made by two-dimensional (2D) materials are proven to shrink diodes’ sizes down to atomic scale, but lattice mismatching at the interfaces between component materials impedes their rectification performances. Here we report a high-performance diode of Sn x Mo 1− x S 2 /MoS 2 lateral heterostructures fabricated via one-step chemical vapor deposition technique. Sn atoms are selectively doped at the edges of MoS 2 crystals to form Sn x Mo 1− x S 2 that have the same lattice constant with respect to that of MoS 2 . Schottky barriers are formed by depositing gold contacts on Sn x Mo 1− x S 2 and MoS 2 crystals but with distinct barriers’ heights, which leads to primary transport of charge carriers in one direction. By controlling the doping concentration and electrical gate voltage ( V g ), we tune the alignment of Fermi level between MoS 2 and Sn x Mo 1− x S 2 , and achieve adjustable rectification ratio up to 10 4 ( I 3 V / I −3 V , V g = 60 V). Impressively, the diode also exhibits excellent photovoltaic and self-powered photo-detective applications. The heterojunction diode exhibits high responsivity of 0.16 A W −1 and detectivity of 6.4 × 10 10 Jones under 650 nm laser illumination. Our work provides a potential pathway for constructing (onto)electronic circuits of 2D materials.