Negative Differential Resistance in van der Waals Heterostructures Due to Moiré-Induced Spectral Reconstruction

Photovoltaic Effect in Graphene/MoS2/Si Van der Waals Heterostructures

This paper presents a study on the photovoltaic effect of a graphene/MoS2/Si double heterostructure, grown by rapid chemical vapor deposition. It was found that the double junctions of the graphene/MoS2 Schottky junction and the MoS2/Si heterostructure played important roles in enhancing the device’s performance. They allowed more electron-hole pairs to be efficiently generated, separated, and ...

High Photovoltaic Quantum Efficiency in Ultrathin van der Waals Heterostructures.

We report experimental measurements for ultrathin (<15 nm) van der Waals heterostructures exhibiting external quantum efficiencies exceeding 50% and show that these structures can achieve experimental absorbance >90%. By coupling electromagnetic simulations and experimental measurements, we show that pn WSe2/MoS2 heterojunctions with vertical carrier collection can have internal photocarrier co...

Two-Dimensional Semiconductor Optoelectronics Based on van der Waals Heterostructures

Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDCs) and black phosphorous have drawn tremendous attention as an emerging optical material due to their unique and remarkable optical properties. In addition, the ability to create the atomically-controlled van der Waals (vdW) heterostructures enables realizing novel optoelectronic devices that are distinct from con...

Heterostructures based on inorganic and organic van der Waals systems

Thermionic Energy Conversion Based on Graphene van der Waals Heterostructures

Seeking for thermoelectric (TE) materials with high figure of merit (or ZT), which can directly converts low-grade wasted heat (400 to 500 K) into electricity, has been a big challenge. Inspired by the concept of multilayer thermionic devices, we propose and design a solid-state thermionic devices (as a power generator or a refrigerator) in using van der Waals (vdW) heterostructure sandwiched b...