Type II Homo-Type Bi₂O₂Se Nanosheet/InSe Nanoflake Heterostructures for Self-Driven Broadband Visible–Near-Infrared Photodetectors

Abstract

Bi 2 O 2 Se nanosheets, an emerging ternary non-van der Waals two-dimensional (2D) material, have garnered considerable research attention in recent years owing to their robust air stability, narrow indirect bandgap, high mobility, and diverse intriguing properties. However, most of them show high dark current and relatively low light on/off ratio and slow response speed because of the large charge carrier concentration and bolometric effect, hindering their further application in low-energy-consuming optoelectronics. Herein, a homotype van der Waals heterostructure based on exfoliated n-InSe integrated with chemical vapor deposition (CVD)grown n-Bi 2 O 2 Se nanosheets that have type II band alignment was fabricated. The efficient interfacial charge separation, strong interlayer coupling, and effective built-in electric field across the heterointerface demonstrated excellent, stable, and broadband self-driven photodetection in the range 400−1064 nm. Specifically, a high responsivity (R) of 75.2 mA•W −1 and a high specific detectivity (D*) of 1.08 × 10 12 jones were achieved under 405 nm illumination. Additionally, a high R of 13.3 mA•W −1 and a high D* of 2.06 × 10 11 jones were achieved under 980 nm illumination. Meanwhile, an ultrahigh I light /I dark ratio over 10 5 and a fast response time of 5.8/15 ms under 405 nm illumination confirmed the excellent photosensitivity and fast response behavior. Furthermore, R could be enhanced to 13.6 and 791 mA•W −1 under 405 and 980 nm illumination at a drain−source voltage (V ds ) of 1 V, respectively, originating from a lower potential barrier. This study suggested that the Bi 2 O 2 Se nanosheet/InSe nanoflake homotype heterojunction can offer potential applications in next-generation broadband photodetectors that consume low energy and exhibit high performance.

Ultrasensitive Near-Infrared Polarization Photodetectors with Violet Phosphorus/InSe van der Waals Heterostructures

“…Achieving a fast photoresponse as well as high R under the NIR spectrum is still a bottleneck in 2D vdW heterostructures for photodetectors. Here, we compare the R and response time with InSe-based vdW heterostructures such as gate/InSe, 37 InSe/ PdSe 2 , 28 InSe/ReSe 2 , 38 InSe/BP, 39 GQDs/InSe, 40 Bi 2 O 2 Se/ InSe, 41 InSe/Ge, 42 InSe/graphene, 43 SnSe/InSe, 44 and InSe/ WSe 2 /SnS 2 45 in the NIR spectrum (Figure 5f). It is clearly evident that our devices such as VP/InSe and VP/Gr/InSe vdW heterostructure-based photodetectors demonstrate considerable detection performance in the NIR spectrum.…”

Vertical 1T’‐WTe2/WS2 Schottky‐Barrier Phototransistor with Polarity‐Switching Behavior

“…It can be also indicated that the rectification behavior with and without gate modulation is probably originated from the WTe 2 /WS 2 interface. [ 48 ] Benefiting from the ambipolar polarity of WS 2 and the semi‐metallic property of WTe 2 , the transfer characteristics of the SBJ will be diversified and controlled by the V ds polarity. As shown in Figure 2b, the 1T’‐WTe 2 /WS 2 channel shows asymmetric ambipolar characteristics and different doping types of majority carriers, which are determined by the V ds polarity.…”

High Performance Self‐Powered and Vis–Infrared Broadband Photodetectors Based on MoTe2/InSe Van der Waals Heterostructure

“…These structures exhibit substantially improved performance compared to individual components, all without the need to consider lattice mismatching. [26] Numerous studies have demonstrated that the construction of vdWH by stacking different 2D materials enables the realization of wide-spectrum and self-powered photodetection, such as MoS 2 /WS 2 , [27] PdSe 2 /MoSe 2 , [28] Bi 2 O 2 Se /InSe, [29] and MoSe 2 /FePS 3 . [30] InSe is a potential 2D material for photoelectric devices due to its advantages of high carrier mobility, excellent photoelectric response, flexibility, piezo-phototronic effect, and good air stability.…”

“…These structures exhibit substantially improved performance compared to individual components, all without the need to consider lattice mismatching. [ 26 ] Numerous studies have demonstrated that the construction of vdWH by stacking different 2D materials enables the realization of wide‐spectrum and self‐powered photodetection, such as MoS 2 /WS 2 , [ 27 ] PdSe 2 /MoSe 2 , [ 28 ] Bi 2 O 2 Se /InSe, [ 29 ] and MoSe 2 /FePS 3 . [ 30 ]…”