Hot‐carrier engineering for two‐dimensional integrated infrared optoelectronics

Abstract Plasmonic hot carrier engineering holds great promise for advanced infrared optoelectronic devices. The process of hot carrier transfer has the potential to surpass the spectral limitations of semiconductors, enabling detection of sub‐bandgap infrared photons. By harvesting hot carriers prior to thermalization, energy dissipation is minimized, leading to highly efficient photoelectric conversion. Distinguished from conventional band‐edge carriers, the ultrafast interfacial transfer and ballistic transport of hot carriers present unprecedented opportunities for high‐speed photoelectric conversion. However, a complete description on the underlying mechanism of hot‐carrier infrared optoelectronic device is still lacking, and the utilization of this strategy for tailoring infrared response is in its early stages. This review aims to provide a comprehensive overview of the generation, transfer and transport dynamics of hot carriers. Basic principles of hot‐carrier conversion in heterostructures are discussed in detail. In addition, progresses of two‐dimensional (2D) infrared hot‐carrier optoelectronic devices are summarized, with a specific emphasis on photodetectors, solar cells, light‐emitting devices and novel functionalities through hot‐carrier engineering. Furthermore, challenges and prospects of hot‐carrier device towards infrared applications are highlighted.