2D materials beyond graphene toward Si integrated infrared optoelectronic devices.

Since the discovery of graphene in 2004, it has become a worldwide hot topic due to its fascinating properties. However, the zero band gap and weak light absorption of graphene strictly restrict its applications in optoelectronic devices. In this regard, semiconducting two-dimensional (2D) materials are thought to be promising candidates for next-generation optoelectronic devices. Infrared (IR) light has gained intensive attention due to its vast applications, including night vision, remote sensing, target acquisition, optical communication, etc. Consequently, the generation, modulation, and detection of IR light are crucial for practical applications. Due to the van der Waals interaction between 2D materials and Si, the lattice mismatch of 2D materials and Si can be neglected; consequently, the integration process can be achieved easily. Herein, we review the recent progress of semiconducting 2D materials in IR optoelectronic devices. Firstly, we introduce the background and motivation of the review. Then, the suitable materials for IR applications are presented, followed by a comprehensive review of the applications of 2D materials in light emitting devices, optical modulators, and photodetectors. Finally, the problems encountered and further developments are summarized. We believe that milestone investigations of IR optoelectronics based on 2D materials beyond graphene will emerge soon, which will bring about great industrial revelations in 2D material-based integrated nanodevice commercialization.