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1.
Fangfang Cui Qingliang Feng Jinhua Hong Renyan Wang Yu Bai Xiaobo Li Dongyan Liu Yu Zhou Xing Liang Xuexia He Zhongyue Zhang Shengzhong Liu Zhibin Lei Zonghuai Liu Tianyou Zhai Hua Xu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(46)
Chemical vapor deposition growth of 1T′ ReS2x Se2(1?x ) alloy monolayers is reported for the first time. The composition and the corresponding bandgap of the alloy can be continuously tuned from ReSe2 (1.32 eV) to ReS2 (1.62 eV) by precisely controlling the growth conditions. Atomic‐resolution scanning transmission electron microscopy reveals an interesting local atomic distribution in ReS2x Se2(1?x ) alloy, where S and Se atoms are selectively occupied at different X sites in each Re‐X6 octahedral unit cell with perfect matching between their atomic radius and space size of each X site. This structure is much attractive as it can induce the generation of highly desired localized electronic states in the 2D surface. The carrier type, threshold voltage, and carrier mobility of the alloy‐based field effect transistors can be systematically modulated by tuning the alloy composition. Especially, for the first time the fully tunable conductivity of ReS2x Se2(1?x ) alloys from n‐type to bipolar and p‐type is realized. Owing to the 1T′ structure of ReS2x Se2(1?x ) alloys, they exhibit strong anisotropic optical, electrical, and photoelectric properties. The controllable growth of monolayer ReS2x Se2(1?x ) alloy with tunable bandgaps and electrical properties as well as superior anisotropic feature provides the feasibility for designing multifunctional 2D optoelectronic devices. 相似文献
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Pin Tian Libin Tang Kar Seng Teng Jinzhong Xiang Shu Ping Lau 《Advanced Materials Technologies》2019,4(7)
Graphene has been widely used as electrodes and active layers in optoelectronics due to its diverse excellent performances, such as high mobility, large thermal conductivity, and high specific surface area. Methodology for constructing p–n junction has become an important consideration in improving the performance of optoelectronic devices and broadening of its application in related fields. Currently, graphene‐based p–n junctions have been explored and different structures have also been investigated. Herein, the recent progress on graphene homogeneous p–n junction is summarized, ranging from preparation of front‐end materials (e.g., p‐ and n‐type graphene) to building of planar and vertical p–n junctions. Furthermore, p–n junction via electrical modulation is described. The requirements for building the graphene homogeneous p–n junction, and the advantages and drawbacks of the different structures of the p–n junction are also discussed. Finally, a preferential technique to fabricate high performance p‐ and n‐type graphene and building of the p–n junction is evaluated. This paper therefore provides an important indication on the future direction on the application of graphene in optoelectronics. 相似文献
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Kenji Nagao Atsushi Sakuda Akitoshi Hayashi Hirofumi Tsukasaki Shigeo Mori Masahiro Tatsumisago 《Advanced Materials Interfaces》2019,6(8)
All‐solid‐state batteries attract significant attention owing to their potential to realize an energy storage system with high safety and energy density. In this paper, a mechanochemical synthesis of novel amorphous positive electrode materials of the Ni‐rich LiNi1−x−yMnxCoyO2 (NMC)–Li2SO4 system suitable for oxide‐type all‐solid‐state batteries is reported. Through the mechanochemical treatment with Li2SO4, excellent formabilities of the electrode materials as those of ductile solid electrolytes are obtained. Owing to the deformability of the active material, a good electrode/electrolyte interface is provided simply by pressing at room temperature. In all‐oxide solid‐state cells using 80NMCs·20Li2SO4 (mol%) positive electrode materials, the cell capacity increases with the Ni content in the NMC. The all‐solid‐state cell using the 80NMC811·20Li2SO4 positive electrode active material exhibits a high capacity larger than 250 mAh g−1 in a voltage range of 1.6–4.8 V versus Li at 100 °C. Furthermore, bulk‐type all‐oxide solid‐state batteries (Li4Ti5O12/80NMC532·20Li2SO4 (mol%)) successfully function as secondary batteries with excellent cycle performances. 相似文献
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June Yeong Lim Atiye Pezeshki Sehoon Oh Jin Sung Kim Young Tack Lee Sanghyuck Yu Do Kyung Hwang Gwan‐Hyoung Lee Hyoung Joon Choi Seongil Im 《Advanced materials (Deerfield Beach, Fla.)》2017,29(30)
Recently, α‐MoTe2, a 2D transition‐metal dichalcogenide (TMD), has shown outstanding properties, aiming at future electronic devices. Such TMD structures without surface dangling bonds make the 2D α‐MoTe2 a more favorable candidate than conventional 3D Si on the scale of a few nanometers. The bandgap of thin α‐MoTe2 appears close to that of Si and is quite smaller than those of other typical TMD semiconductors. Even though there have been a few attempts to control the charge‐carrier polarity of MoTe2, functional devices such as p–n junction or complementary metal–oxide–semiconductor (CMOS) inverters have not been reported. Here, we demonstrate a 2D CMOS inverter and p–n junction diode in a single α‐MoTe2 nanosheet by a straightforward selective doping technique. In a single α‐MoTe2 flake, an initially p‐doped channel is selectively converted to an n‐doped region with high electron mobility of 18 cm2 V?1 s?1 by atomic‐layer‐deposition‐induced H‐doping. The ultrathin CMOS inverter exhibits a high DC voltage gain of 29, an AC gain of 18 at 1 kHz, and a low static power consumption of a few nanowatts. The results show a great potential of α‐MoTe2 for future electronic devices based on 2D semiconducting materials. 相似文献
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Dechao Geng Xiaoxu Zhao Zhongxin Chen Weiwei Sun Wei Fu Jianyi Chen Wei Liu Wu Zhou Kian Ping Loh 《Advanced materials (Deerfield Beach, Fla.)》2017,29(35)
As a new member of the MXene group, 2D Mo2C has attracted considerable interest due to its potential application as electrodes for energy storage and catalysis. The large‐area synthesis of Mo2C film is needed for such applications. Here, the one‐step direct synthesis of 2D Mo2C‐on‐graphene film by molten copper‐catalyzed chemical vapor deposition (CVD) is reported. High‐quality and uniform Mo2C film in the centimeter range can be grown on graphene using a Mo–Cu alloy catalyst. Within the vertical heterostructure, graphene acts as a diffusion barrier to the phase‐segregated Mo and allows nanometer‐thin Mo2C to be grown. Graphene‐templated growth of Mo2C produces well‐faceted, large‐sized single crystals with low defect density, as confirmed by scanning transmission electron microscopy (STEM) measurements. Due to its more efficient graphene‐mediated charge‐transfer kinetics, the as‐grown Mo2C‐on‐graphene heterostructure shows a much lower onset voltage for hydrogen evolution reactions as compared to Mo2C‐only electrodes. 相似文献
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Sb1?xBixSI, an isostructural material with the well‐known quasi‐1D SbSI, possesses good semiconductive and ferroelectric properties but is not applied in solar cells. Herein, solar cells based on alloyed Sb0.67Bi0.33SI (ASBSI) as a light harvester are fabricated. ASBSI is prepared through the reaction of bismuth triiodide in N,N‐dimethylformamide solution with an antimony trisulfide film deposited on a mesoporous (mp)‐TiO2 electrode via chemical bath deposition at 250 °C under an argon or nitrogen atmosphere; the alloy exhibits a promising bandgap (1.62 eV). The best performing cell fabricated with poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)] as the hole‐transporting layer shows 4.07% in a power conversion efficiency (PCE) under the standard illumination conditions of 100 mW cm?2. The unencapsulated cells exhibit good comprehensive stability with retention of 92% of zjr initial PCE under ambient conditions of 60% relative humidity over 360 h, 93% after 1 sun illumination for 1254 min, and 92% after storage at 85 °C in air for 360 h. 相似文献
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《Advanced Materials Interfaces》2018,5(13)
Exploring efficient Pt‐free hydrogen evolution reaction (HER) electrocatalyst with low cost and earth‐abundance is a critical challenge. Herein, highly active and stable Mo/α‐MoC1−x catalyst is synthesized via a simple pyrolysis of a MoO3/ethylenediamine hybrid precursor in reductive atmosphere. The as‐prepared Mo/α‐MoC1−x shows excellent HER activity with a low onset potential of −75 mV (vs reversible hydrogen electrode), a small Tafel slope of 81.7 mV dec−1, as well as good stability in acid electrolytes owing to the synergistic effect of Mo and α‐MoC1−x. This novel structure is a candidate for other energy related fields and this simple synthesis method can be further applied for the synthesis of other hybrid catalysts. 相似文献
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Binmin Wu Xudong Wang Hongwei Tang Wei Jiang Yan Chen Zhen Wang Zhuangzhuang Cui Tie Lin Hong Shen Weida Hu Xiangjian Meng Wenzhong Bao Jianlu Wang Junhao Chu 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(22)
MoS2, one of the most valued 2D materials beyond graphene, shows potential for future applications in postsilicon digital electronics and optoelectronics. However, achieving hole transport in MoS2, which is dominated by electron transport, is always a challenge. Here, MoS2 transistors gated by electrolyte gel exhibit the characteristics of hole and electron transport, a high on/off ratio over 105, and a low subthreshold swing below 50 mV per decade. Due to the electrolyte gel, the density of electrons and holes in the MoS2 channel reaches ≈9 × 1013 and 8.85 × 1013 cm?2, respectively. The electrolyte gel‐assisted MoS2 phototransistor exhibits adjustable positive and negative photoconductive effects. Additionally, the MoS2 p–n homojunction diode affected by electrolyte gel shows high performance and a rectification ratio over 107. These results demonstrate that modifying the conductance of MoS2 through electrolyte gel has great potential in highly integrated electronics and optoelectronic photodetectors. 相似文献
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Ti‐Ta based alloys are potential high‐temperature shape memory materials with operation temperatures above 100 °C. In this study, the room temperature fabrication of Ti‐Ta thin films showing a reversible martensitic transformation and a high temperature shape memory effect above 200 °C is reported. In contrast to other shape memory thin films, no further heat treatment is necessary to obtain the functional properties. A disordered α″ martensite (orthorhombic) phase is formed in the as‐deposited co‐sputtered Ti70Ta30, Ti68Ta32 and Ti67Ta33 films, independent of the substrate. A Ti70Ta30 free‐standing film shows a reversible martensitic transformation, as confirmed by temperature–dependent XRD measurements during thermal cycling between 125 °C to 275 °C. Furthermore, a one‐way shape memory effect is qualitatively confirmed in this film. The observed properties of the Ti‐Ta thin films make them promising for applications on polymer substrates and especially in microsystem technologies. 相似文献
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《Advanced Materials Interfaces》2018,5(18)
2D van der Waals materials are promising for various electronic and optoelectronic devices because of their thickness‐dependent mobility and tunable bandgap. Recently, heterojunction structures based on 2D van der Waals materials have exhibited their potential for photovoltaic applications as ultrathin p–n diodes. In this study, the photovoltaic effect of a multilayer black phosphorus (BP)/WS2 p–n heterojunction device is demonstrated under the 405 nm laser illumination and the AM 1.5 solar spectrum. The diode‐like characteristics and photovoltaic effect rely on balance between charge carriers in the heterojunction device, by showing the highest performance at the balance position. The gate‐tunable heterojunction device shows a high current rectification of 103 and an external quantum efficiency of 4.4% under the 405 nm laser illumination, and a photovoltaic efficiency of 4.6% under the AM 1.5 solar spectrum. This work suggests that the balancing of the charge carriers in the 2D heterojunction p–n diode is highly prioritized to fabricate high‐performance photovoltaic device. 相似文献
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Xiaochun Huang Bing Liu Jiaqi Guan Guangyao Miao Zijian Lin Qichang An Xuetao Zhu Weihua Wang Jiandong Guo 《Advanced materials (Deerfield Beach, Fla.)》2018,30(30)
Two‐dimensional (2D) in‐plane p–n junctions with a continuous interface have great potential in next‐generation devices. To date, the general fabrication strategies rely on lateral epitaxial growth of p‐ and n‐type 2D semiconductors. An in‐plane p–n junction is fabricated with homogeneous monolayer Te at the step edge on graphene/6H‐SiC(0001). Scanning tunneling spectroscopy reveals that Te on the terrace of trilayer graphene is p‐type, and it is n‐type on monolayer graphene. Atomic‐resolution images demonstrate the continuous lattice of the junction, and mappings of the electronic states visualize the type‐II band bending across the space‐charge region of 6.2 nm with a build‐in field of 4 × 105 V cm?1. The reported strategy can be extended to other 2D semiconductors on patternable substrates for designed fabrication of in‐plane junctions. 相似文献
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Hong‐Kyu Seo Sung‐Yong Min Himchan Cho Min‐Ho Park Young‐Hoon Kim Tae‐Woo Lee 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(10):1999-2005
Although graphene can be easily p‐doped by various adsorbates, developing stable n‐doped graphene that is very useful for practical device applications is a difficult challenge. We investigated the doping effect of solution‐processed (4‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzoimidazol‐2‐yl)phenyl)dimethylamine (N‐DMBI) on chemical‐vapor‐deposited (CVD) graphene. Strong n‐type doping is confirmed by Raman spectroscopy and the electrical transport characteristics of graphene field‐effect transistors. The strong n‐type doping effect shifts the Dirac point to around ‐140 V. Appropriate annealing at a low temperature of 80 ºC enables an enhanced electron mobility of 1150 cm2 V?1 s?1. The work function and its uniformity on a large scale (1.2 mm × 1.2 mm) of the doped surface are evaluated using ultraviolet photoelectron spectroscopy and Kelvin probe mapping. Stable electrical properties are observed in a device aged in air for more than one month. 相似文献
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Xiaoting Zhu Yu Zhang Xiangwei Ren Jiarong Yao Siyu Guo Lijuan Zhang Dong Wang Guangwei Wang Xiaotao Zhang Rongjin Li Wenping Hu 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(34)
Ambipolar organic field‐effect transistors (OFETs) are vital for the construction of high‐performance all‐organic digital circuits. The bilayer p–n junction structure, which is composed of separate layers of p‐ and n‐type organic semiconductors, is considered a promising way to realize well‐balanced ambipolar charge transport. However, this approach suffers from severely reduced mobility due to the rough interface between the polycrystalline thin films of p‐ and n‐type organic semiconductors. Herein, 2D molecular crystal (2DMC) bilayer p–n junctions are proposed to construct high‐performance and well‐balanced ambipolar OFETs. The molecular‐scale thickness of the 2DMC ensures high injection efficiency and the atomically flat surface of the 2DMC leads to high‐quality p‐ and n‐layer interfaces. Moreover, by controlling the layer numbers of the p‐ and n‐type 2DMCs, the electron and hole mobilities are tuned and well‐balanced ambipolar transport is accomplished. The hole and electron mobilities reach up to 0.87 and 0.82 cm2 V?1 s?1, respectively, which are the highest values among organic single‐crystalline double‐channel OFETs measured in ambient air. This work provides a general route to construct high‐performance and well‐balanced ambipolar OFETs based on available unipolar materials. 相似文献
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Azadipyrromethene‐Based Zn(II) Complexes as Nonplanar Conjugated Electron Acceptors for Organic Photovoltaics 
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下载免费PDF全文 Zhenghao Mao Wasana Senevirathna Jia‐Yu Liao Jun Gu Sameer Vajjala Kesava Changhe Guo Enrique D. Gomez Geneviève Sauvé 《Advanced materials (Deerfield Beach, Fla.)》2014,26(36):6290-6294
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Jae‐Bok Lee Yi Rang Lim Ajit K. Katiyar Wooseok Song Jongsun Lim Sukang Bae Tae‐Wook Kim Seoung‐Ki Lee Jong‐Hyun Ahn 《Advanced materials (Deerfield Beach, Fla.)》2019,31(43)
Functional van der Waals heterojunctions of transition metal dichalcogenides are emerging as a potential candidate for the basis of next‐generation logic devices and optoelectronics. However, the complexity of synthesis processes so far has delayed the successful integration of the heterostructure device array within a large scale, which is necessary for practical applications. Here, a direct synthesis method is introduced to fabricate an array of self‐assembled WSe2/MoS2 heterostructures through facile solution‐based directional precipitation. By manipulating the internal convection flow (i.e., Marangoni flow) of the solution, the WSe2 wires are selectively stacked over the MoS2 wires at a specific angle, which enables the formation of parallel‐ and cross‐aligned heterostructures. The realized WSe2/MoS2‐based p–n heterojunction shows not only high rectification (ideality factor: 1.18) but also promising optoelectrical properties with a high responsivity of 5.39 A W?1 and response speed of 16 µs. As a feasible application, a WSe2/MoS2‐based photodiode array (10 × 10) is demonstrated, which proves that the photosensing system can detect the position and intensity of an external light source. The solution‐based growth of hierarchical structures with various alignments could offer a method for the further development of large‐area electronic and optoelectronic applications. 相似文献
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H. Mas Ayu R. Daud T. Kurniawan J. Alias S. Izman A. Shah M. Anwar 《Materialwissenschaft und Werkstofftechnik》2019,50(3):254-259
Biomedical grade of cobalt based alloy have found a plethora of applications as medical devices especially in dental and articulation joints like in total ankle, knee and hip arthroplasty. However, the long‐term performance of this material is highly dependent on their ability to withstand in harsh aqueous environment effects such as corrosion and wear once they are used inside a human body. Loss of surface integrity and subsequent leaching of toxic metal ions as well as particles to the surrounding tissues may undermine biocompatibility of metallic implants, also potentially causing untimely loss of mechanical function and device failure. In this study, a biomedical grade of Co?Cr?Mo alloy surface was treated with various surface modification techniques such as chemical etching and mechanical roughening in order to improve its biocompatibility. Investigation was done to study which surface modification techniques possesses the positive effect in cell growth and exhibit excellent cell response on Co?Cr?Mo alloy. In‐vitro study showed that human osteoblast cells grown with good adherence and spread out with an intimate contact on the chemical treated surface after 14 days of incubation. It is believed that porous structure with grooves owned by chemical treated surface helps in anchoring the cells to the substrate surface and facilitates cells growth since more protein molecules expected to have more sites on this surface. Whilst on mechanical roughened surface, the cells appeared to show slightly less extended cell membranes and the cells remained retarded. 相似文献