Air-Stable Flexible Photodetector Based on MXene–Cs₃Bi₂I₉ Microplate Schottky Junctions for Weak-Light Detection

Abstract

Weak-light detection technology is widely used in various fields, including industry, high-energy physics, precision analysis, and reflection imaging. Metal−semiconductor−metal (MSM) photodetectors demonstrate high detectivity and high response speed and are one of the suitable structures for the preparation of weak-light detectors. However, traditional MSM photodetectors tend to exhibit high dark currents, which are not conducive to performance improvement. Here, a MXene− Cs 3 Bi 2 I 9 −MXene weak-light detector is proposed. Based on the MXene−Cs 3 Bi 2 I 9 Schottky junctions, the dark current is reduced by 2 orders of magnitude and the responsivity is significantly improved compared with the traditional Cr/Au−Cs 3 Bi 2 I 9 −Cr/Au MSM photodetector. The device demonstrates excellent photodetection capacity with a photoresponsivity of 6.45 A W −1 , a specific detectivity of 9.45 × 10 11 Jones, and a fast response speed of 0.27/2.32 ms. Especially, the device yielded a superior weak-light detectable limit of 10.66 nW cm −2 and demonstrated excellent optical communication capability. Moreover, such a flexible device shows little degradation in photodetection performance after extreme bending for 4500 cycles, proving remarkable bending endurance and flexibility. The obtained results highlight the great potential of such Cs 3 Bi 2 I 9 /MXene devices as a stable and environmentally friendly candidate for weak-light detection. KEYWORDS: Cs 3 Bi 2 I 9 microplates, Ti 3 C 2 T x MXene, flexible, weak-light detection, stability

Toward High Bias‐Stress Stability P‐Type GaSb Nanowire Field‐Effect‐Transistor for Gate‐Controlled Near‐Infrared Photodetection and Photocommunication

“…The encoded information “ S ”, “ D ”, and “ U ” is transformed to the American Standard Code for Information Interchange (ASCII) codes and sent to a signal generator which will output square wave voltage signals in Figure S9 (Supporting Information). [ 47 ] The voltage signals are applied to the gate terminal of 1 min AlO x treated GaSb NWFET. As shown in Figure 6d, the encoded information is effectively transmitted and signals are exactly identified as “01010011”, “01000100”, and “01010101”, which represent “ S ”, “ D ”, and “ U ”, respectively.…”

High‐Performance Broadband Flexible Photodetectors Based on Ti3C2Tx MXene/Pyramidal Thin Si Heterostructures with Light Trapping Effect for Heart Rate Detection

“…[40] Very recently, a flexible photodetector composed of an MXene-Cs 3 Bi 2 I 9 -MXene heterostructure has been successfully fabricated. [41] As compared to a conventional Cr/Au-Cs 3 Bi 2 I 9 -Cr/Au device, the detector with MXene electrodes exhibits two orders of magnitude reduced dark current, as well as greatly improved photoresponse. The flexible detector also demonstrates excellent bending endurance and flexibility with insignificant degradation in optoelectronic properties after 4500 cycles bending.…”

2D Ti3C2-MXene Nanosheets/ZnO Nanorods for UV Photodetectors

“…MXenes are a new branch of layered materials with fascinating electronic and optical properties and solution processability, allowing them to be widely used in various electronic and optoelectronic devices, such as transistors, photocatalysts, , photosensors, , and LEDs. , MXenes, including Ti 3 C 2 , MoC 2 , V 3 C 2 , and Ti 4 N 3 , are layered transition-metal carbides, nitrides, or carbonitrides that are produced when MAX phases exfoliate. MXenes are superior to Au nanoparticles as Schottky electrode materials because of their tunable work function (1.6–8.0 eV), outstanding optical transparency, and metallic conductivity. , As transparent Schottky contacts, MXenes have already been integrated with Si, GaAs, TiO 2 , perovskites, and so on. A multiquantum well MXene–GaN–MXene PD exhibits an increased switching ratio of 3 orders of magnitude, with a response rate and specific detectivity of 64.6 A W –1 and 1.93 × 10 12 jones, respectively .…”

“…MXenes are superior to Au nanoparticles as Schottky electrode materials because of their tunable work function (1.6−8.0 eV), outstanding optical transparency, and metallic conductivity. 43,44 As transparent Schottky contacts, MXenes have already been integrated with Si, 45 GaAs, 46 TiO 2 , 47 perovskites, 48 and so on. A multiquantum well MXene−GaN−MXene PD exhibits an increased switching ratio of 3 orders of magnitude, with a response rate and specific detectivity of 64.6 A W −1 and 1.93 × 10 12 jones, respectively.…”