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Polymeric iodobismuthates {[Bi <sub/>3</sub> I <sub/>10</sub> ]} and {[BiI <sub/>4</sub> ]} with N-heterocyclic cations: promising perovskite-like photoactive materials for electronic devices
摘要： A screening of the reactions between BiI3 and iodide salts of different N-alkylated heterocycles (pyridine, quinoline, isoquinoline) resulted in the preparation and structural characterization of six novel iodobismuthate complexes, including two compounds exhibiting an unprecedented {[Bi3I10]} polymeric moiety. It has been shown that the chemical composition and structure of the iodobismuthates significantly affect their optical and electronic properties. The narrowest band gaps (Eg) were revealed by {[Bi3I10]} iodobismuthates, while the compounds incorporating {[BiI4]} polymeric frameworks showed 0.2–0.3 eV wider Eg. GIXRD analysis evidenced that all three iodobismuthates investigated in thin films show mainly the horizontal (parallel to the substrate) orientation of the 1D polymeric Bi–I frameworks. Such arrangement blocks the charge transport in vertical direction (orthogonal to the substrate) since the conductive Bi–I chains are separated with insulating bulky organic cations. As a consequence, standard planar junction solar cells based on new iodobismuthates revealed low power conversion efficiencies approaching 0.12% only. However, strong in-plane photoconductivity observed for iodobismuthates enabled the fabrication of efficient planar photodetectors, which paves a way to the practical use of this exotic family of materials. Most importantly, the presented systematic study revealed the most general guidelines for future rational design of perovskite-like materials for emerging generation of environment-friendly perovskite photovoltaics emphasizing the importance of the isotropic charge transport in the films of 3D materials and achieving proper orientation of 1D and 2D frameworks with respect to the charge collecting electrodes in anisotropic low dimensional systems.
关键词： photodetectors,perovskite-like materials,iodobismuthates,structural characterization,charge transport,photovoltaics
更新于2025-09-19 17:15:36
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Incorporating Aluminum Plasmonic Nanohemisphere Arrays into Organic Ultraviolet Photodetectors for Improved Photoresponse
摘要： Aluminum nanostructures, which support surface plasmon resonances in the UV spectral range, were incorporated into conventional organic UV photodetectors with a structure of indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly(9,9-dioctyl?uorene-alt-bithiophene) (F8T2):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM)/LiF/Al. Nanohemisphere arrays (NHSAs) were imprinted into the top surface of the soft organic active layer, thus transferring the pattern to the subsequently thermally deposited layers of LiF and Al. NHSA-top devices and ?at-top control devices were investigated by 3-dimensional ?nite-di?erence time-domain (3D-FDTD) electromagnetic simulations. Improved UV active layer absorbance and enhanced electric ?elds in the nanohemispheric region at the top of the active layer were shown for devices with the NHSA-top. The impact of the NHSA-top was found to be more signi?cant for devices with thin active layers and to gradually decrease with increasing active layer thickness. Fabricated NHSA-top devices with thin active layers exhibited improved photoresponse in terms of external quantum e?ciency, speci?c detectivity and on?o? response speed compared to ?at-top devices under 330 nm illumination and 0 to ?1 V bias. The method developed in this work provides a versatile and e?ective way to incorporate plasmonic nanostructures into optoelectronic devices to enhance device performance.
关键词： enhanced photoresponse,aluminum plasmonic nanostructures,organic photodetectors,nanoimprinting,ultraviolet photodetectors
更新于2025-09-19 17:13:59
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Investigation of structural and optoelectronic properties of n-MoS2/p-Si sandwiched heterojunction photodetector
摘要： Molybdenum disulphide (MoS2), a member of the transition metal dichalcogenides family has shown excellent optoelectronic properties with direct or indirect bandgaps in visible range as well as good absorption in its 2-dimensional (2D) form. In this work, a polycrystalline MoS2 thin film is fabricated by radio frequency magnetron sputtering. X-ray diffraction (XRD) analysis of the fabricated sample reveals two hexagonal structured peaks along the (100) and (110) planes, while energy-dispersive X-ray (EDX) spectroscopy confirms a non-stoichiometric MoS2 film with a thickness of 300 nm. Raman shifts are observed at the E1 2g and A1g phonon modes, located at 374.37 cm?1 and 407.75 cm?1 respectively. A sandwiched heterojunction photodetector with a SLG/n-MoS2/p-Si structure is fabricated and illuminated with violet light at 441 nm. The device exhibits significant optoelectronic properties at various laser powers at a 10 V bias voltage. The maximum value of the photocurrent is calculated as 0.79 μA, with the responsivity as 10.4 mAW?1 and detectivity of 6.74 × 109 Jones at an intensity of 0.004 mW/cm2. These results highlight the adaptability of the current technique that will help realize large-scale production as well as allow for the development of advanced optoelectronic devices.
关键词： Photodetectors,Thin films,RF sputtering,MoS2,Raman
更新于2025-09-19 17:13:59
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Multicolor Broadband and Fast Photodetector Based on InGaAsa??Insulatora??Graphene Hybrid Heterostructure
摘要： Broadband light detection is crucial for a variety of optoelectronic applications in modern society. As an important-near infrared (NIR) photodetector, InGaAs PIN photodiodes demonstrate high detection performance. However, they have a limited response range because of optical absorption by the window layer or substrate. To exploit the broadband absorption capability of narrow-bandgap InGaAs, a phototransistor based on a hybrid InGaAs-SiO2-graphene heterostructure is presented. In this system, graphene serves as a transparent conducting channel to sense optical absorption in the InGaAs. In contrast to InGaAs PIN photodiodes, the hybrid InGaAs phototransistor demonstrates multicolor photodetection over a broadband wavelength range from the ultraviolet to NIR. Furthermore, it manifests a high photoresponsivity of above 103 A W?1 under weak light irradiation, a large external quantum efficiency, and a fast response speed of 200 kHz. The results pave the way for the development of high-performance broadband photodetectors based on mixed-dimensional heterostructures.
关键词： InGaAs,photodetectors,graphene
更新于2025-09-19 17:13:59
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Ultrafast and broadband photodetectors based on a perovskite/organic bulk heterojunction for large-dynamic-range imaging
摘要： Organic-inorganic hybrid perovskite (OIHP) photodetectors that simultaneously achieve an ultrafast response and high sensitivity in the near-infrared (NIR) region are prerequisites for expanding current monitoring, imaging, and optical communication capabilities. Herein, we demonstrate photodetectors constructed by OIHP and an organic bulk heterojunction (BHJ) consisting of a low-bandgap nonfullerene and polymer, which achieve broadband response spectra up to 1 μm with a highest external quantum efficiency of approximately 54% at 850 nm, an ultrafast response speed of 5.6 ns and a linear dynamic range (LDR) of 191 dB. High sensitivity, ultrafast speed and a large LDR are preeminent prerequisites for the practical application of photodetectors. Encouragingly, due to the high-dynamic-range imaging capacity, high-quality visible-NIR actual imaging is achieved by employing the OIHP photodetectors. We believe that state-of-the-art OIHP photodetectors can accelerate the translation of solution-processed photodetector applications from the laboratory to the imaging market.
关键词： Organic-inorganic hybrid perovskite,ultrafast response,photodetectors,high-dynamic-range imaging,broadband response,near-infrared
更新于2025-09-19 17:13:59
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Enhancement of photodetectors devices for silicon nanostructure from study effect of etching time by photoelectrochemical etching technique
摘要： Porous silicon (PS) prepared from n-type silicon via photoelectrochemical etching (PECE) technique. The morphology properties of PS specimens that formed with different etching time has been study utilize Scanning electron microscopy (SEM) and it show that the Layer of pore has sponge like stricture and the average pore diameter of PS layer rising with increase etching time. The X-ray diffraction (XRD) pattern indicated the nanocrystaline of the specimens, during these results; we showed improve behavior of PS photodetectors on a range of wavelengths.
关键词： Morphological properties,Porous silicon,Photodetectors,Photoelectrochemical etching
更新于2025-09-19 17:13:59
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A multiscale materials-to-systems modeling of polycrystalline PbSe photodetectors
摘要： We present a physics based multiscale materials-to-systems model for polycrystalline PbSe photodetectors that connects fundamental material properties to circuit level performance metrics. From experimentally observed ?lm structures and electrical characterization, we ?rst develop a band structure model that explains carrier-type inversion and large carrier lifetimes in sensitized ?lms. The unique band structure of the photosensitive ?lm causes separation of generated carriers with holes migrating to the inverted PbSejPbI2 interface, while electrons are trapped in the bulk of the ?lm intergrain regions. These ?ows together form the 2-current theory of photoconduction that quantitatively captures the I(cid:2)V relationship in these ?lms. To capture the e?ect of pixel scaling and trapped carrier blocking, we develop a model for the metallic contacts with the detector ?lms based on the relative workfunction di?erences. We also develop detailed models for various physical parameters such as mobility, lifetime, quantum e?ciency, noise, etc. that connect the detector performance metrics such as responsivity R and speci?c detectivity D* intimately with material properties and operating conditions. A compact Verilog-A based SPICE model is developed which can be directly combined with advanced digital Read-Out Integrated Circuit cell designs to simulate and optimize high performance Focal Plane Arrays which form a critical component in the rapidly expanding market of self-driven automotive, internet of things security, and embedded applications.
关键词： polycrystalline materials,PbSe photodetectors,carrier-type inversion,multiscale modeling,quantum efficiency,band structure,SPICE model
更新于2025-09-19 17:13:59
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Waveguide-integrated van der Waals heterostructure photodetector at telecom wavelengths with high speed and high responsivity
摘要： Intensive efforts have been devoted to the exploration of new optoelectronic devices based on two-dimensional transition-metal dichalcogenides (TMDCs) owing to their strong light–matter interaction and distinctive material properties. In particular, photodetectors featuring both high-speed and high-responsivity performance are of great interest for a vast number of applications such as high-data-rate interconnects operated at standardized telecom wavelengths. Yet, the intrinsically small carrier mobilities of TMDCs become a bottleneck for high-speed application use. Here, we present high-performance vertical van der Waals heterostructure-based photodetectors integrated on a silicon photonics platform. Our vertical MoTe2–graphene heterostructure design minimizes the carrier transit path length in TMDCs and enables a record-high measured bandwidth of at least 24 GHz under a moderate bias voltage of –3 V. Applying a higher bias or employing thinner MoTe2 flakes boosts the bandwidth even to 50 GHz. Simultaneously, our device reaches a high external responsivity of 0.2 A W–1 for incident light at 1,300 nm, benefiting from the integrated waveguide design. Our studies shed light on performance trade-offs and present design guidelines for fast and efficient devices. The combination of two-dimensional heterostructures and integrated guided-wave nano photonics defines an attractive platform to realize high-performance optoelectronic devices, such as photodetectors, light-emitting devices and electro-optic modulators.
关键词： transition-metal dichalcogenides,photodetectors,silicon photonics,van der Waals heterostructures,two-dimensional materials
更新于2025-09-19 17:13:59
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PbE (E = S, Se) Colloidal Quantum Dot-Layered 2D Material Hybrid Photodetectors
摘要： Hybrid lead chalcogenide (PbE) (E = S, Se) quantum dot (QD)-layered 2D systems are an emerging class of photodetectors with unique potential to expand the range of current technologies and easily integrate into current complementary metal-oxide-semiconductor (CMOS)-compatible architectures. Herein, we review recent advancements in hybrid PbE QD-layered 2D photodetectors and place them in the context of key findings from studies of charge transport in layered 2D materials and QD films that provide lessons to be applied to the hybrid system. Photodetectors utilizing a range of layered 2D materials including graphene and transition metal dichalcogenides sensitized with PbE QDs in various device architectures are presented. Figures of merit such as responsivity (R) and detectivity (D*) are reviewed for a multitude of devices in order to compare detector performance. Finally, a look to the future considers possible avenues for future device development, including potential new materials and device treatment/fabrication options.
关键词： photodetectors,phosphorene,infrared,PbS,graphene,layered 2D materials,TMDs,colloidal quantum dots,PbSe
更新于2025-09-19 17:13:59
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Industrial Applications of Nanomaterials || Nanomaterials-based UV photodetectors
摘要： Photodetectors are essential elements applied in video imaging, optical communications, biomedical imaging, security, night-vision, gas sensing, and motion detection, which possess the ability to transform light into electrical signals precisely. As the scale and diversity of application areas are growing, the need for innovative photodetection platform technologies with higher performance in terms of speed, efficiency or wavelength range, as well as material flexibility, transparency, and complementary metal-oxide-semiconductor (CMOS) integrability, is becoming more critical. In the past decades, extensive efforts have been devoted to explore the next generation of photodetector materials, such as In2Te3, ZnO, and GaN, with low noise, high photosensitivity, and good stability. However, many of these novel photodetector materials still suffer from limited photocurrent and photoresponse speed.
关键词： Nanomaterials,Schottky contacts,photoconductive gain,photodetection mechanism,photoresistors,linear dynamic range,responsivity,external quantum efficiency,photodiodes,specific detectivity,UV photodetectors
更新于2025-09-19 17:13:59