Broadband high-performance vertical WS1.08Se0.92/Si heterojunction photodetector with MXene electrode

All-Solution Fabricated MXene/GaAs Self-Driven Photodetector with an Inserted Graphene Oxide Interface Layer

As a novel two-dimensional material, MXene has attracted much attention due to its special photoelectric properties. The formation of van der Waals Schottky heterojunctions between MXene and bulk semiconductor materials is a promising method for manufacturing photodetectors. Furthermore, the deterioration in device performance resulting from the Schottky interfacial state can be effectively mitigated by implementing interface engineering techniques. In this study, we develop a Ti3C2Tx/GO/GaAs van der Waals Schottky junction photodetector with a graphene oxide interfacial barrier layer, which is fabricated using an all-solution method on a prepatterned substrate. The insertion of the GO interfacial layer effectively decreases the dark-current noise, thereby maintaining an ultralow dark current at zero bias, achieving a large specific detectivity of 1.4 × 1013 Jones and an ultrafast response speed of 41.7/40.0 μs. Moreover, the device exhibits a broad-band response spectrum spanning from 405 to 980 nm. The infrared photoresponse exceeding the absorption edge of GaAs results from the excitation of hot electrons by the plasmon effect in the MXene film. Due to the simple preparation and high specific detectivity, the Ti3C2Tx/GO/GaAs self-driven photodetector is suitable for the monitoring of weak light signals and can be used as the basis for many light detection applications.

Recent advance of high-quality perovskite nanostructure and its application in flexible photodetectors

Flexible photodetectors (PDs) have garnered increasing attention for their potential applications in diverse fields, including weather monitoring, smart robotics, smart textiles, electronic eyes, wearable biomedical monitoring devices, and so on. Notably, perovskite nanostructures have emerged as a promising material for flexible PDs due to their distinctive features, such as a large optical absorption coefficient, tunable band gap, extended photoluminescence decay time, high carrier mobility, low defect density, long exciton diffusion lengths, strong self-trapped effect, good mechanical flexibility, and facile synthesis methods. In this review, we first introduce various synthesis methods for perovskite nanostructures and elucidate their corresponding optical and electrical properties, encompassing quantum dots, nanocrystals, nanowires, nanobelts, nanosheets, single-crystal thin films, polycrystalline thin films, and nanostructured arrays. Furthermore, the working mechanism and key performance parameters of optoelectronic devices are summarized. The review also systematically compiles recent advancements in flexible PDs based on various nanostructured perovskites. Finally, we present the current challenges and prospects for the development of perovskite nanostructures-based flexible PDs.

A polarization-sensitive, high on/off ratio and self-powered photodetector based on Nb2CTxand Nd2CTx@MoS2

MXene two-dimensional materials have been widely used in energy storage, catalysis, sensing and other fields, Nb2C as a typical two-dimensional MXene material, its exploration in the field of optoelectronics is still in its infancy, especially Nb2C-based photodetectors are still to be developed. This paper demonstrates that two-dimensional films based on few-layer Nb2C have a photoelectric response in the wavelength range from visible to near-infrared. We have found that the light response performance can be easily adjusted by controlling the thickness of the spin-coated film, and that Nb2C photodetectors show great advantages in terms of wide bandwidth, polarization response, high switching ratio, etc. By adjusting the material concentration and sample thickness, the photocurrent can reach up to 330 nA, the switching ratio can reach 410, and the responsivity can reach 8.3 × 10-4A W-1. In the polarization characteristic test, an extinction ratio of 7.6 can be obtained. By adjusting the content of that doped MoS2quantum dot, the dark current can reach 7.6 × 10-13A, and the switching ratio can reach 3 × 105, which can be increased by 700 times. The above results show that the few-layer Nb2C nanosheets can be used as optoelectronic detectors in the visible to near-infrared bands, which further broadens the application prospects of two-dimensional MXene.