Light-controlled van der Waals tunnel junctions: mechanisms, architectures, functionalities, and opportunities

TL;DR

This review explores light-controlled van der Waals tunnel junctions, detailing their mechanisms, architectures, functionalities, and future opportunities in quantum transport and optoelectronics.

Contribution

It provides a comprehensive overview of photo-assisted tunneling in vdW heterostructures, highlighting new functionalities and future research directions.

Findings

Understanding of photo-assisted transport mechanisms

Demonstration of vdW tunnel junction functionalities

Potential for quantum-geometric and moire-based applications

Abstract

The phenomenon of electron tunneling has long been central to quantum transport and continues to provide a powerful framework for understanding and controlling electronic processes in solids. When combined with optical excitation, tunneling becomes a particularly rich platform for experiments, because light can drive nonequilibrium carrier populations and open transport pathways that are inaccessible without optical excitation. The emergence of van der Waals (vdW) materials has greatly expanded this opportunity by enabling atomically thin heterostructures with clean interfaces, engineered barriers, and highly tunable band alignment. In this review, we discuss the fundamental mechanisms of photo-assisted transport and the realization of vdW tunnel junctions, and show how they provide electrical access to nonequilibrium dynamics and collective excitations in quantum materials. We further examine emerging functionalities including photodetection, tunneling-driven light emission, sensing, and memory. Finally, we present a forward-looking perspective on new opportunities such as quantum-geometric probes, twist-resolved spectroscopy, moire ferroelectricity, and scalable architectures for computing and sensing.