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Infrared photodetectors have been widely applied in various fields, including thermal imaging, biomedical imaging, and communication. Van der Waals (vdW) integration based on 2D materials provides a new solution for high-performance infrared photodetectors due to the versatile device configurations and excellent photoelectric properties. In recent years, great progress has been made in infrared photodetectors based on vdW integration. In this review, recent progress in vdW integration-based infrared photodetectors is presented. First, the working mechanisms and advantages of photodetectors with different structures and band alignments are presented. Then, the recent progress of vdW integration-based infrared photodetectors is reviewed, focusing on 2D/nD (n = 0, 1, 2, 3) vdW integration, and the band engineering as well as the performance of the photodetectors are discussed in detail. Finally, a summary is delivered, and the challenges and future directions of vdW integration-based infrared photodetectors are provided.

2D materials have shown great promise for next-generation high-performance photodetectors. However, the performance of photodetectors based on 2D materials is generally limited by the tradeoff between photoresponsivity and photodetectivity. Here, a novel junction field-effect transistor (JFET) photodetector consisting of a PdSe 2 gate and MoS 2 channel is constructed to realize high responsivity and high detectivity through effective modulation of top junction gate and back gate. The JFET exhibits high carrier mobility of 213 cm 2 V −1 s −1 . What is more, the high responsivity of 6 × 10 2 A W −1 , as well as the high detectivity of 10 11 Jones, are achieved simultaneously through the dual-gate modulation. The high performance is attributed to the modulation of the depletion region by the dual-gate, which can effectively suppress the dark current and enhance the photocurrent, thereby realizing high detectivity and responsivity. The JFET photodetector provides a new approach to realize photodetectors with high responsivity and detectivity.

Developing spatially controlled and universal p-type doping of transition-metal dichalcogenides (TMDs) is critical for optoelectronics. Here, a facile and universal p-doping strategy via Sn4+ ions exchanging is proposed and the p-doping of PdSe2 is demonstrated systematically as the example. The polarity of PdSe2 can be modulated from n-type to bipolar and p-type precisely by changing the concentration of SnCl4 solution. The modulation effectively reduces the electron concentration and improves the work function by ∼72 meV. In addition, the solution-processable route makes the spatially controlled doping possible, which is demonstrated by constructing the lateral PdSe2 p-n homojunction with rectification behavior and photovoltaic effect. This p-doping method has been further proved in modulating various TMDs including WSe2, WS2, ReSe2, MoSe2, MoTe2, and PtSe2. This spatially controlled and universal method based on Sn atoms substitution realizes p-type doping of TMDs.

Intercalation is an effective approach to tune the physical and chemical properties of 2D materials due to their abundant van der Waals gaps that can host high‐density intercalated guest matters. This approach has been widely employed to modulate the optical, electrical, and photoelectrical properties of 2D materials for their applications in electronic and optoelectronic devices. Thus it is necessary to review the recent progress of the intercalation strategy in 2D materials and their applications in devices. Herein, various intercalation strategies and the novel properties of the intercalated 2D materials as well as their applications in electronics and optoelectronics are summarized. In the end, the development tendency of this promising approach for 2D materials is also outlined.