A Novel Phototransistor Device with Dual Active Layers Composited of CsPbBr3 and ZnO Quantum Dots

Abstract

Taking advantage of a large light absorption coefficient, long charge carrier diffusion length and low-cost solution processing, all-inorganic halides perovskite CsPbBr3 quantum dots (QDs) are combined with a ZnO QD film to construct a high-performance photodetector. In this work, a novel photodetector device based on transistor structure with dual active layers composed of CsPbBr3 and ZnO film is proposed. In this structure, CsPbBr3 film functions as the light-absorbing layer and ZnO film acts as the conducting layer. Owing to the high electron mobility and hole-blocking nature of the ZnO QDs film, the photo-induced electron-hole pairs can be separated efficiently. As a result, the device exhibits high performance with response of 43.5 A/W, high detection up to 5.02 × 1011 Jones and on/off ratio of 5.6 × 104 under 365 nm light illumination. Compared with the ZnO-only phototransistor (the photodetector with the structure of transistor) the performance of the CsPbBr3 phototransistor showed significant improvement, which is superior to the majority of photodetectors prepared by perovskite. This work demonstrates that the ZnO QDs film can be applied in the photodetector device as a functional conducting layer, and we believe that the hybrid CsPbBr3/ZnO phototransistor would promote the development of low-cost and high-performance photodetectors.

CsPbX3‐ITO (X = Cl, Br, I) Nano‐Heterojunctions: Voltage Tuned Positive to Negative Photoresponse

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Due to its excellent physical and chemical properties, the halide all-inorganic CsPbX 3 (X = Cl, Br, I) perovskite semiconductors are intensively studied and the applications are penetrating many fields such as solar cells, [1][2][3][4][5][6] light emitting diodes, [7][8][9][10] lasers, [11][12][13] chemical sensors, [14][15][16] catalysis, [17][18][19] photo/X-ray/γ-ray detectors, [20][21][22][23][24][25][26][27] transistors, [28][29][30] and computing. [31,32] Driven by this trend, various types of perovskite based heterojunctions, for example, perovskite-metal, perovskite-semiconductor, or perovskite-insulator heterojunctions have been developed and All-Inorganic perovskite CsPbX 3 (X = Cl, Br, I) quantum dots (QDs) have attracted tremendous attention in the past few years for their appealing performance in optoelectronic applications.

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Emerging Perovskite Materials with Different Nanostructures for Photodetectors

“…There are two mature methods to fabricate perovskite QDs: hotinjection and ligand-assisted reprecipitation. [23,53,54] Hot-injection method is conducted under high reaction temperature and inert atmosphere. Generally, perovskite QDs are synthesized by swiftly injecting cesium oleate into an octadecene solution containing PbX 2 , oleic acid (OA), and oleylamine (OAm) at a high temperature.…”

“…There are several methods to promote the EQE or responsivity of phototransistors, such as integrating graphene or other 2D layered materials, and organic materials with perovskites or doping CNTs or QDs in the perovskite layers. [120,52,54] Surendran and co-workers developed a hybrid graphene-perovskite photodetector which embraced the excellent photon absorption properties of perovskites and high carrier mobility of graphene in a single device. [120] They used CsPbBr x I 3−x NCs as a photoabsorber and graphene as a transport layer.…”

Quantum Dots and Applications

“…One of the articles is related to QD materials chemistry and QD-based EL devices [7]. Two articles then focus on QD-based photovoltaic devices [8,9], and the last article proposes a new driving mechanism for a QD device [10]. First, Kim et al explored methods to tune PL wavelength of InP/ZnSe/ZnS QDs through Cu doping and their size control.…”

“…This article demonstrates the importance of well-designed architectures for high-performance devices. [8]. Moraitis et al evaluated the correlation between the absorption bandwidth of several state-of-the-art QDs and the transmitted sunlight spectrum by Monte Carlo simulations.…”