Epitaxial Growth of PbS Nanocrystals from PbI₂ Nanosheet Templates and Its Application in Fast Near‐Infrared Photodetectors

Abstract

Heterostructures of 0D/2D materials synergistically combine the advantages of two different materials, and photodetectors (PDs) based on such heterostructures demonstrate superior detection properties as compared to those based on each individual material. Here, a facile solution method is proposed for the fabrication of 0D/2D heterostructures to overcome the limitations of the traditional chemical vapor deposition method. The 0D PbS nanocrystals (NCs) are epitaxially grown from 2D‐PbI2 nanosheet templates by a simple wet‐chemical sulfuration process. The resulting heterojunction PDs demonstrate wide detection range up to 2000 nm, a fast photoresponse of ≈400 µs, and a specific detectivity of more than 1012 Jones. The superior device performances are attributed to the underneath PbI2 layer, which can not only be used as the precursor layer but also help to passivate the defect states of PbS NCs. More importantly, the developed Structured II device with Au–PbI2 Schottky contact effect can suppress the dark current of PD to extend its depletion region and improve the response speed. Overall, this study demonstrates a novel strategy for the growth of 0D/2D heterostructures in conjunction with fast near‐infrared detection, which surmount the limitations of photoconductive detectors in terms of large‐scale synthesis and response speed.

Fast Response Self-Powered UV–Vis–NIR Broadband Photodetector Based on a Type II Heterojunction of AgIn5Se8/FePSe3

“…As an important information sensing device, photodetectors have become a significant component in the miniaturized electronics industry and have wide applications in the fields of image recognition, optoelectronic systems, and biological chemical sensors. − The high-performance photodetectors with UV–Vis–NIR integration are expected to greatly reduce the volume of the spectral measurement system and become an important direction for the development of photodetectors. Furthermore, a conventional photodetector requires an external power supply, which induces the circuit complexity of designing the devices and limits their application in special environments and situations. , Therefore, it is particularly important for fabricating self-powered high-performance photodetectors as they do not require an external voltage when operating and thus reduce energy consumption.…”

In Situ Growth of PbS/PbI2 Heterojunction and Its Photoelectric Properties

“…Efficiently obtaining accurate multi-band information in complex environments is extremely important. Thus, the photoelectric detection system with dual-band or multi-band fusion were invented [8][9][10][11][12]. However, the previously developed dual-band or multi-band detection systems are usually composed of two or more independent detection systems.…”

Ferroelectric-gated MoSe2 photodetectors with high photoresponsivity

“…In recent years, there are many efforts to improve the performance of * Authors to whom any correspondence should be addressed. photodetectors, such as structure optimization [11,12], energy band engineering [13,14], surface treatment [15,16] and so on. The responsivity of MoSe 2 photodetector was improved by 276% by modifying the surface of MoSe 2 with gold nanoseeds [16].…”