Monolayer MoS2 is a direct band gap semiconductor with potential applications in optoelectronics and photonics. MoS2 also has a large optical nonlinearity. However, the atomic thickness of the monolayer limits the strength of the measured functional signals, such as the photocurrent or photoluminescence, in optoelectronic devices. Here, we show that photocurrent in monolayer MoS2 can be induced by sub-band gap photons by depositing Au nanoparticles on it. In this system, the nonlinear light-matter interaction in Au nanoparticles enhanced by the localized surface plasmons results in the generation of supercontinuum, which is reabsorbed by MoS2 due to efficient resonant energy transfer. Au nanoparticle assisted photocurrent is more than an order of magnitude larger than two-photon photocurrent in monolayer MoS2. Optimization of the shape, size and composition of the nanoparticle has the potential to enhance the photocurrent significantly with the prospect of applications in the detection of NIR photons, and related technologies including optical telecommunication.
@article{arxiv.2511.22175,
title = {2D MoS$_2$/Au interfaces for enhanced opto-electronic response with sub-bandgap photons},
author = {Jinlei Wu and Wei Huang and Ahsan Ali and Yuhong Chen and Elissaios Stavrou and Zuoti Xie and Jinhui Zhong and Khadga Jung Karki},
journal= {arXiv preprint arXiv:2511.22175},
year = {2025}
}