Abstract
Over the past two decades, two-dimensional (2D) van der Waals (vdW) semiconductors have garnered significant attention in the field of light sources due to their unique optoelectronic properties, such as high excitonic binding energy, tunable bandgaps, and strong optical anisotropy. These properties make 2D vdW semiconductors highly promising for next-generation light sources, offering advantages like enhanced efficiency, wavelength tunability, and polarization control. In this review, we summarize the development of various 2D vdW material-based light sources and their modulation mechanisms. We first provide an overview of excitonic properties and light-emission principles that aim to develop light sources with low-power, high-efficiency. Next, we discuss advances in 2D semiconductor lasers, including intralayer and interlayer exciton lasers, cavity-free systems, and exciton-polariton sources. We then look into single-photon emission and their integration into on-chip systems, followed by studies on nonlinear optical properties like high-order harmonic generation and P-band emission. Additionally, we cover advancements in electrically pumped light sources. The review concludes with an outlook on future developments of 2D vdW semiconductor light sources.