Unveiling intrinsic bulk photovoltaic effect in atomically thin ReS2

TL;DR

This paper demonstrates the intrinsic bulk photovoltaic effect in atomically thin ReS2 devices, achieving high responsivity without external tuning, supported by theoretical calculations, and suggests broader applicability to other non-centrosymmetric van der Waals materials.

Contribution

The study provides the first clear experimental evidence of intrinsic BPVE in atomically thin ReS2, with high responsivity and minimal extrinsic effects, supported by theoretical analysis.

Findings

Intrinsic responsivity of 1 mA/W in visible range

Minimal contact resistance in fabricated devices

Theoretical support for experimental results

Abstract

The bulk photovoltaic effect (BPVE) offers a promising avenue to surpass the efficiency limitations of current solar cell technology. However, disentangling intrinsic and extrinsic contributions to photocurrent remains a significant challenge. Here, we fabricate high-quality, lateral devices based on atomically thin ReS2 with minimal contact resistance, providing an optimal platform for distinguishing intrinsic bulk photovoltaic signals from other extrinsic photocurrent contributions originating from interfacial effects. Our devices exhibit large bulk photovoltaic performance with intrinsic responsivities of 1 mA/W in the visible range, without the need for external tuning knobs such as strain engineering. Our experimental findings are supported by theoretical calculations. Furthermore, our approach can be extrapolated to investigate the intrinsic BPVE in other non-centrosymmetric van der Waals materials, paving the way for a new generation of efficient light-harvesting devices.