Strategies for Air‐Stable and Tunable Monolayer MoS₂‐Based Hybrid Photodetectors with High Performance by Regulating the Fully Inorganic Trihalide Perovskite Nanocrystals

Abstract

environmentalmonitoring, infrared imaging, and optical communication. [1,2] Semiconductor nanomaterials and hybrid films (HFs) have attracted much attention for their potential applications in novel photodetectors. [3] In the family of graphene-like 2D materials used in novel optoelectronics, layered transition metal dichalcogenides (TMDs) have a broad application prospect [4][5][6] due to their unique physical features and optoelectronic properties. [7] As a representative material of TMDs, MoS 2 possesses several advantages, including a direct bandgap of ≈1.8 eV, high carrier mobility, and favorable chemical stability, [8] which are especially suitable for sensing light. However, the atomically thin nature of 2D MoS 2 crystals results in an extremely inefficient light-trapping ability, [9] which is a fatal flaw for photodetector devices. The practical application of MoS 2 -based photodetectors is also hindered by severely limited photoresponse and detecting capability, slow response rate, [10] etc. As a result, many efforts have been made to optimize the performance of atomic-layer MoS 2 -based optoelectronics. [10][11][12][13][14][15][16][17][18] Many studies have shown that the use of hybrid photodetectors (HPs) can mitigate the disadvantages of atomically thin MoS 2 crystals. Under the synergistic effect of multimaterials, hybrid MoS 2 -based devices show improved response rates and responsivities. [10][11][12][13][14][15][16][17][18] For example, the photoresponse rate of a MoS 2 -based device increased by almost three orders of magnitude by constructing the heterojunctions with GaSe flakes, [10] and a greatly increased responsivity (10 6 A W −1 ) was achieved in a TiO 2 -encapsulated MoS 2 transistor-modified by HgTe quantum dots. [18] Therefore, a heterojunction structure improves the performance of MoS 2 -based photodetectors, and the successful integration of dissimilar materials may pave the way toward successful high-performance hybrid optoelectronic devices.Currently, lead halide perovskite materials have been widely used in optoelectronic applications, especially solar cells and lightemitting diodes (LEDs), owing to their attractive optoelectronic characteristics, such as high optical absorbance, long diffusion length of charge carriers, and high carrier mobility. [19][20][21] Perovskite materials with different dimensions have been integrated into optoelectronic devices to improve the performance. [22] The past several years have seen the rapid development of fully inorganic trihalide perovskite nanocrystals (PNCs) in the field of hybrid optoelectronic devices due to their outstanding photophysical properties and environmental stability. In this study, novel and easily implementable strategies are proposed to regulate the photoresponse performance of monolayer MoS 2 /PNC hybrid photodetectors (HPs) without the photogating effect. The optoelectronic properties of these HPs are tuned by regulating the characteristic factors of colloidal PNCs (solution concentration and surface ligand content), ...

Controllable Synthesis of All Inorganic Lead Halide Perovskite Nanocrystals with Various Appearances in Multiligand Reaction System

“…Over the past decade, organic-inorganic hybrid perovskite has continuously attracted research attention due to its energy applications [1][2][3][4], which has, in turn, triggered a research boom on the controllable synthesis, photophysical properties, and optoelectronic devices of lead halide perovskite [5][6][7][8][9]. In 2015, Kovalenko et al successfully synthesized all-inorganic cesium lead halide (CsPbX 3 , X = Cl, Br, I) perovskite nanocrystals (PNCs) for the first time [10].…”

Perovskite Quantum Dot‐Ta2NiSe5 Mixed‐Dimensional Van Der Waals Heterostructures for High‐Performance Near‐Infrared Photodetection

“…Efforts to overcome these limitations include surface passivation, phase-pattern engineering, and hybrid photodetectors. [20][21][22][23] Mixed-dimensional van der Waals heterostructures (MvdWHs) can mitigate the shortcoming of atomically thin 2D materials. [24,25] MvdWHs composed of size-tunable 0D semiconductor quantum dots (QDs) and 2D vdWHs have various advantages, such as easy preparation, reduced Coulombic interactions, and less-constrained interfacial states.…”

“…[26,27] Organic lead-halide perovskite QDs (PQDs) have excellent optoelectrical properties, such as large absorption coefficients, long diffusion lengths, and high carrier mobilities. [23,28,29] Combining the 0D PQDs with 2D MvdWHs may generate unusual devices. For example, FAPbBr 3 QDs and graphene MvdWHs fabricated by Song et al in 2018 exhibited a broadband response over 405-980 nm and a 520 nm responsivity of 1.15 × 10 5 A W -1 .…”

Light-triggered interfacial charge transfer and enhanced photodetection in CdSe/ZnS quantum dots/MoS₂ mixed-dimensional phototransistors

“…Figure 2(i) shows the energy band diagram of QD/MoS 2 heterostructures. The conduction band and valence band of MoS 2 monolayer are reported to be 4.25 eV and 6.1 eV in previous work, respectively 26 . While for QDs, the conductance and valence bands are reported to be 3.2−3.4 eV and 5.3−5.5 eV, respectively 39,40 .…”