共查询到20条相似文献,搜索用时 375 毫秒
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Kiana Montazeri Marc Currie Louisiane Verger Pouya Dianat Michel W. Barsoum Bahram Nabet 《Advanced materials (Deerfield Beach, Fla.)》2019,31(43)
2D transition metal carbides, known as MXenes, are transparent when the samples are thin enough. They are also excellent electrical conductors with metal‐like carrier concentrations. Herein, these characteristics are exploited to replace gold (Au) in GaAs photodetectors. By simply spin‐coating transparent Ti3C2‐based MXene electrodes from aqueous suspensions onto GaAs patterned with a photoresist and lifted off with acetone, photodetectors that outperform more standard Au electrodes are fabricated. Both the Au‐ and MXene‐based devices show rectifying contacts with comparable Schottky barrier heights and internal electric fields. The latter, however, exhibit significantly higher responsivities and quantum efficiencies, with similar dark currents, hence showing better dynamic range and detectivity, and similar sub‐nanosecond response speeds compared to the Au‐based devices. The simple fabrication process is readily integratable into microelectronic, photonic‐integrated circuits and silicon photonics processes, with a wide range of applications from optical sensing to light detection and ranging and telecommunications. 相似文献
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Jinyou Xu Katya Rechav Ronit Popovitz‐Biro Iftach Nevo Yishay Feldman Ernesto Joselevich 《Advanced materials (Deerfield Beach, Fla.)》2018,30(20)
1D core–shell heterojunction nanostructures have great potential for high‐performance, compact optoelectronic devices owing to their high interface area to volume ratio, yet their bottom‐up assembly toward scalable fabrication remains a challenge. Here the site‐controlled growth of aligned CdS–CdSe core–shell nanowalls is reported by a combination of surface‐guided vapor–liquid–solid horizontal growth and selective‐area vapor–solid epitaxial growth, and their integration into photodetectors at wafer‐scale without postgrowth transfer, alignment, or selective shell‐etching steps. The photocurrent response of these nanowalls is reduced to 200 ns with a gain of up to 3.8 × 103 and a photoresponsivity of 1.2 × 103 A W?1, the fastest response at such a high gain ever reported for photodetectors based on compound semiconductor nanostructures. The simultaneous achievement of sub‐microsecond response and high‐gain photocurrent is attributed to the virtues of both the epitaxial CdS–CdSe heterojunction and the enhanced charge‐separation efficiency of the core–shell nanowall geometry. Surface‐guided nanostructures are promising templates for wafer‐scale fabrication of self‐aligned core–shell nanostructures toward scalable fabrication of high‐performance compact photodetectors from the bottom‐up. 相似文献
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Krisztina Szendrei Fabrizio Cordella Maksym V. Kovalenko Michaela Böberl Günther Hesser Maksym Yarema Dorota Jarzab Oleksandr V. Mikhnenko Agnieszka Gocalinska Michele Saba Francesco Quochi Andrea Mura Giovanni Bongiovanni Paul W. M. Blom Wolfgang Heiss Maria Antonietta Loi 《Advanced materials (Deerfield Beach, Fla.)》2009,21(6):683-687
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Xien Liu Eun Kwang Lee Joon Hak Oh 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(18):3700-3706
The maximum responsivity of a pure monolayer graphene‐based photodetector is currently less than 10 mA W?1 because of small optical absorption and short recombination lifetime. Here, a graphene hybrid photodetector functionalized with a photoactive ruthenium complex that shows an ultrahigh responsivity of ≈1 × 105 A W?1 and a photoconductive gain of ≈3 × 106 under incident optical intensity of the order of sub‐milliwatts is reported. This responsivity is two orders of magnitude higher than the precedent best performance of graphene‐based photodetectors under a similar incident light intensity. Upon functionalization with a 4‐nm‐thick ruthenium complex, monolayer graphene‐based photodetectors exhibit pronounced n‐type doping effect due to electron transfer via the metal?ligand charge transfer (MLCT) from the ruthenium complex to graphene. The ultrahigh responsivity is attributed to the long lifetime and high mobility of the photoexcited charge carriers. This approach is highly promising for improving the responsivity of graphene‐based photodetectors. 相似文献
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Generalized Scheme for High Performing Photodetectors with a p‐Type 2D Channel Layer and n‐Type Nanoparticles 下载免费PDF全文
Jingyuan Jia Sumin Jeon Jaeho Jeon Jiao Xu Young Jae Song Jeong Ho Cho Byoung Hun Lee Jin Dong Song Hyung‐Jun Kim Euyheon Hwang Sungjoo Lee 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(9)
A generalized scheme for the fabrication of high performance photodetectors consisting of a p‐type channel material and n‐type nanoparticles is proposed. The high performance of the proposed hybrid photodetector is achieved through enhanced photoabsorption and the photocurrent gain arising from its effective charge transfer mechanism. In this paper, the realization of this design is presented in a hybrid photodetector consisting of 2D p‐type black phosphorus (BP) and n‐type molybdenum disulfide nanoparticles (MoS2 NPs), and it is demonstrated that it exhibits enhanced photoresponsivity and detectivity compared to pristine BP photodetectors. It is found that the performance of hybrid photodetector depends on the density of NPs on BP layer and that the response time can be reduced with increasing density of MoS2 NPs. The rising and falling times of this photodetector are smaller than those of BP photodetectors without NPs. This proposed scheme is expected to work equally well for a photodetector with an n‐type channel material and p‐type nanoparticles. 相似文献
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Yan Zhao Chenglong Li Jizhong Jiang Boming Wang Liang Shen 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(26)
Tin(Sn)‐based perovskite is currently considered one of the most promising materials due to extending the absorption spectrum and reducing the use of lead (Pb). However, Sn2+ is easily oxidized to Sn4+ in atmosphere, causing more defects and degradation of perovskite materials. Herein, double‐sided interface engineering is proposed, that is, Sn‐Pb perovskite films are sandwiched between the phenethylammonium iodide (PEAI) in both the bottom and top sides. The larger organic cations of PEA+ are arranged into a perovskite surface lattice to form a 2D capping layer, which can effectively prevent the water and oxygen to destroy bulk perovskite. Meanwhile, the PEA+ can also passivate defects of iodide anions at the bottom of perovskite films, which is always present but rarely considered previously. Compared to one sided passivation, Sn‐Pb hybrid perovskite photodetectors contribute a significant enhancement of performance and stability, yielding a broadband response of 300–1050 nm, a low dark current density of 1.25 × 10–3 mA cm–2 at –0.1 V, fast response speed of 35 ns, and stability beyond 240 h. Furthermore, the Sn‐Pb broadband photodetectors are integrated in an infrared up‐conversion system, converting near‐infrared light into visible light. It is believed that a double‐sided passivation method can provide new strategies to achieving high‐performance perovskite photodetectors. 相似文献
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A reduced‐order representation of the Poincaré–Steklov operator: an application to coupled multi‐physics problems 下载免费PDF全文
Matteo Aletti Damiano Lombardi 《International journal for numerical methods in engineering》2017,111(6):581-600
This work investigates a model reduction method applied to coupled multi‐physics systems. The case in which a system of interest interacts with an external system is considered. An approximation of the Poincaré–Steklov operator is computed by simulating, in an offline phase, the external problem when the inputs are the Laplace–Beltrami eigenfunctions defined at the interface. In the online phase, only the reduced representation of the operator is needed to account for the influence of the external problem on the main system. An online basis enrichment is proposed in order to guarantee a precise reduced‐order computation. Several test cases are proposed on different fluid–structure couplings. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Photodetectors: High‐Gain and Low‐Driving‐Voltage Photodetectors Based on Organolead Triiodide Perovskites (Adv. Mater. 11/2015) 下载免费PDF全文
Rui Dong Yanjun Fang Jungseok Chae Jun Dai Zhengguo Xiao Qingfeng Dong Yongbo Yuan Andrea Centrone Xiao Cheng Zeng Jinsong Huang 《Advanced materials (Deerfield Beach, Fla.)》2015,27(11):1967-1967
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Light‐Emitting Diodes: Efficient Vacuum‐Processed Light‐Emitting Diodes Based on Carbene–Metal–Amides (Adv. Mater. 35/2018) 下载免费PDF全文
Patrick J. Conaghan S. Matthew Menke Alexander S. Romanov Saul T. E. Jones Andrew J. Pearson Emrys W. Evans Manfred Bochmann Neil C. Greenham Dan Credgington 《Advanced materials (Deerfield Beach, Fla.)》2018,30(35)
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I. El‐Araby Ali T. Lampke D. Wett T. Grund D. Nestler B. Wielage 《Materialwissenschaft und Werkstofftechnik》2014,45(6):445-455
Thermal barrier coatings (TBC) generally consist of a metallic bond coat (BC) and a ceramic top coat (TC). Co–Ni–Cr–Al–Y metallic super alloys and Yttria stabilised zirconia (YSZ) have been widely used as bond coat and top coat for thermal barrier coatings systems, respectively. As a result of long‐term exposure of thermal barrier coatings systems to oxygen‐containing atmospheres at high temperatures, a diffusion of oxygen through the porous ceramic layer occurs and consequently an oxidation zone is formed in the interface between ceramic top coat and metallic bond coat. Alloying components of the BC layer create a so‐called thermally grown oxides layer (TGO). One included oxide type is α‐Al2O3. α‐Al2O3 lowers oxygen diffusion and thus slows down the oxidation process of the bond coat and consequently affects the service life of the coating system positively. The distribution of the alloying elements in the bond coat layer, however, generally causes the formation of mixed oxide phases. The different oxide phases have different growth rates, which cause local stresses, micro‐cracking and, finally, delamination and failure of the ceramic top coat layer. In the present study, a thin Al inter‐layer was deposited by DC‐Magnetron Sputtering on top of the Co–Ni–Cr–Al–Y metallic bond coat, followed by thermal spraying of yttria‐stabilised zirconia (YSZ) as a top coat layer. The deposited Al inter‐layer is meant to transform under operating conditions into a closed layer with high share of α‐Al2O3 that slows down the growth rate of the resulting thermally grown oxides layer. Surface morphology and microstructure characteristics as well as thermal cycling behaviour were investigated to study the effect of the intermediate Al layer on the oxidation of the bond coat compared to standard system. The system with Al inter‐layer shows a smaller thermally grown oxides layer thickness compared to standard system after thermal cycling under same conditions. 相似文献
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A Review on Organic–Inorganic Halide Perovskite Photodetectors: Device Engineering and Fundamental Physics 下载免费PDF全文
The last eight years (2009–2017) have seen an explosive growth of interest in organic–inorganic halide perovskites in the research communities of photovoltaics and light‐emitting diodes. In addition, recent advancements have demonstrated that this type of perovskite has a great potential in the technology of light‐signal detection with a comparable performance to commercially available crystalline Si and III–V photodetectors. The contemporary growth of state‐of‐the‐art multifunctional perovskites in the field of light‐signal detection has benefited from its outstanding intrinsic optoelectronic properties, including photoinduced polarization, high drift mobilities, and effective charge collection, which are excellent for this application. Photoactive perovskite semiconductors combine effective light absorption, allowing detection of a wide range of electromagnetic waves from ultraviolet and visible, to the near‐infrared region, with low‐cost solution processability and good photon yield. This class of semiconductor might empower breakthrough photodetector technology in the field of imaging, optical communications, and biomedical sensing. Therefore, here, the focus is specifically on the critical understanding of materials synthesis, design, and engineering for the next‐stage development of perovskite photodetectors and highlighting the current challenges in the field, which need to be further studied in the future. 相似文献