Two-dimensional(2D) materials have received extensive attention in optoelectronics because of their unique characteristics. However, due to the extremely thin thickness of 2D materials, their optical absorption is limited. In recent years, researchers have used different effects and structures to enhance the optical absorption of 2D materials. Waveguide, as a device to guide and limit light propagation, has been integrated into photodetectors based on 2D materials, and most of them are applied in the infrared spectrum. This article reviews the development of waveguide-integrated photodetectors based on 2D materials, mainly in the infrared spectrum in recent years. Discussions mainly focus on the preparation of materials in waveguide-integrated photodetectors, the design and simulation of waveguide structures, and the research results and applications of waveguide-integrated photodetectors in recent years are summarized. Finally, the challenges and prospects of waveguide-integrated photodetectors are put forward and discussed.

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Two‐dimensional (2D) materials have aroused widespread interest due to the high potential in modern photoelectronics. The strategy for improving the stability of 2D materials in the air, reinforcing formation, and transport of photoexcited carriers would open up promising routes toward flexible facilities. In this paper, surface engineering is executed on 2D InSe by decorating Au species for a lower bandgap allowing for efficient sunlight harvesting and decreased barrier with the substrate for improved electron transport. Moreover, hot electrons produced by Au nanoparticles under light irradiation pour into InSe for boosting photocurrent. Au nanoparticles also serve as conducting bridges in InSe−Au photoanode, where the contact resistance is two orders of magnitude lower than that of InSe electrode. Compared with InSe and other 2D counterparts, InSe−Au flexible photoelectrochemical detectors behave with outstanding performances under sunlight irradiation, including responsibility 55.4 µA W−1, detectivity 4.18 × 109 Jones. Importantly, the working electrode shows excellent ON/OFF switching stability after bending for 5000 times (3 months of storage in the air). This surface engineering provides a general strategy to tailor 2D materials for wearable photoelectronic devices in the future.