Interfacial Assembly of Ti₃C₂T_x/ZnIn₂S₄ Heterojunction for High‐Performance Photodetectors

Abstract

Two‐dimensional (2D) materials have emerged as prospective candidates for electronics and optoelectronics applications as they can be easily fabricated through liquid exfoliation and used to fabricate various structures by further subsequent processing methods in addition to their extraordinary and unique optoelectronic properties. Herein, the Ti3C2Tx/ZIS heterostructure with nanometer‐thick Ti3C2Tx‐MXene and ZnIn2S4 (ZIS) films is fabricated by successive interfacial assembly of liquid exfoliated 2D MXene and ZnIn2S4 nanoflakes. Benefiting from the superior light‐harvesting capability and low dark current of ZnIn2S4, the limited absorbance, large scattering coefficient, and high dark current disadvantages of MXene are ameliorated. Meanwhile, the separation and transport of photogenerated carriers in ZnIn2S4 are improved due to the excellent electrical conductivity of Ti3C2Tx nanoflakes. As a result, the as‐prepared Ti3C2Tx/ZIS heterostructure photodetector has excellent optoelectronic characteristics in terms of a high responsivity of 1.04 mA W−1, a large specific detectivity up to 1 × 1011 Jones, a huge on/off ratio at around 105, and an ultralow dark current at ≈10−12 A. This work demonstrates a convenient method to construct heterostructured photodetectors by liquid exfoliated 2D nanoflakes, the as‐fabricated Ti3C2Tx/ZIS heterostructured photodetectors show promising application potential for low‐cost, reliable, and high‐performance photodetectors.

Sandwiched WS2/MoTe2/WS2 Heterostructure with a Completely Depleted Interlayer for a Photodetector with Outstanding Detectivity

“…The transport path is elongated, and the rise/fall time is extended to 180/190 μs. Notably, this response speed surpasses that of WS 2 , MoTe 2 , and WS 2 /MoTe 2 heterostructure devices (Figure S13), as well as previously reported works, ,− highlighting the superiority of our device architecture. Furthermore, Figure d exhibits the multicycle photoswitching behavior of the heterostructure device in response to the pulsed 635 nm laser.…”

Chloroplast-Inspired Carrier Circulation for Improved Photoelectrochemical Photodetectors Based on Ti2CTx Nanosheets

“…Two-dimensional (2D) layered materials exhibit remarkable physicochemical features, such as improved optical transparency, exceptional electrical conductivity, and superior mechanical strength. − Transition-metal carbides and/or nitrides, also referred to as MXenes, are a new class of 2D materials that possess a number of endearing qualities, including metallic conductivity, mechanical flexibility, hydrophilia, great transmittance, and chemical stability. − In particular, Ti 2 CT x , as one of the many varieties of MXenes, exhibits remarkable semiconducting behavior in terms of strong light absorption in the visible range due to a band gap of 2.32 eV. , Additionally, it has ultrahigh hole mobility of 3.36 × 10 4 cm 2 V –1 s –1 and superhigh carrier mobility of 1 × 10 4 cm 2 V –1 s –1 , which are the highest in the MXene family. − Due to these outstanding electrical and optical properties, Ti 2 CT x is a great candidate for constructing large-area, ultraflexible, high-performance photodetectors. − However, the recombination of photogenerated electron–hole pairs has largely restricted the performance of 2D semiconductor photodetectors, including MXene photodetectors. − To solve this problem, the optical and electrical properties of MXene have been optimized using a variety of methods to improve their photoresponse performance. , Luo et al created van der Waals Schottky junction and chose metal electrodes to adjust MXene as a suitable charge transport layer, and Yu et al increased the specific surface area and active sites of MXene nanosheets by a liquid-phase exfoliation method to improve the photoelectric conversion capability of MXene, respectively. Despite this, due to the limitations of the structure and materials of the photodetector itself, these improvements are relatively limited.…”

Halogenated Ti3C2 MXenes Prepared by Microwave Molten Salt for Hg0 Photo‐Oxidation

“…[9][10][11][12] MXenes is a 2D transition metal carbide, nitride, or carbonitride, widely used in energy storage and catalysis. [13][14][15][16][17] As the first discovered MXene material, Ti 3 C 2 MXene has many hydrophilic functional groups on its surface, [18] making it easy to form heterostructures with other semiconductors. It has excellent metal conductivity and can efficiently transfer charge carriers.…”