Nanoscale Control of Carrier Transport in Monolayer Transition-Metal Dichalcogenide Double Heterostructures.

Tian, Jinpeng; Cheng, Guangming; Tan, Jingtao; Butler, Satya; Liang, Yin; Mao, Haining; Ji, Jaehoon; Kim, Jaerin et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

Heterostructures are fundamental to modern electronics and optoelectronics. Lateral heterostructures of two-dimensional (2D) semiconductors provide a promising platform for monolayer device architecture. However, the carrier transport mechanisms across these lateral heterointerfaces, especially in heterostructures with nanometer-scale dimensions, remain underexplored. Here, we report the synthesis of monolayer transition-metal dichalcogenide lateral double heterostructures (LDHs) with coherent, dislocation-free interfaces and sub-10 nm dimensional control, including WS<sub>2</sub>-MoS<sub>2</sub>-WS<sub>2</sub> and WS<sub>2</sub>-WSe<sub>2</sub>-WS<sub>2</sub>. Using WS<sub>2</sub>-WSe<sub>2</sub>-WS<sub>2</sub> LDHs as a model system, we investigate the electron transport mechanism across the WSe<sub>2</sub> barrier and observe a transition from thermionic emission to direct tunneling as the WSe<sub>2</sub> width decreases to sub-10 nm. Importantly, the effective barrier height can be modulated by the gate voltage and source-drain bias, enabling electrostatic control of charge injections. These findings establish LDHs as a powerful platform for engineering transport within monolayer semiconductors, offering new opportunities for next-generation 2D electronic and quantum devices.