面向柔性电子的形状记忆聚合物

与传统电子器件的刚性相比,柔性电子器件可弯曲、可延展,在诸如可穿戴设备等应用中显示出不可比拟的优势.现有柔性电子器件通常基于宏观平面设计,限制了其发展.形状记忆聚合物作为一类智能材料,具有形状可控、模量可调等特点,在电子器件方面受到了越来越广泛的关注.将形状记忆聚合物引入柔性电子器件,不仅可以更好地调节柔性电子器件的物理性能,还能使器件具有复杂的宏观三维立体结构,从而显示出更强大的功能.此外,形状记忆聚合物在柔性器件的制备上可以起到独特的作用.本文综述了形状记忆聚合物作为柔性电子基体材料和转印图章的发展过程及研究进展,并对该领域的未来发展方向进行展望.     

钙钛矿锰氧化物薄膜应变效应的研究进展

钙钛矿锰氧化物薄膜具有庞磁电阻效应和较大的自旋极化率.对其进行深入研究,将有益于促进自旋电子学器件的发展.在对钙钛矿锰氧化物薄膜研究进行总结回顾的基础上,概述了晶格失配、应力和晶格弛豫之间的关系,介绍了应力效应对钙钛矿锰氧化物薄膜的磁电耦合效应、相分离等物理性质的影响,发现薄膜与衬底间的失配应力和薄膜厚度变化引起的应力弛豫是影响薄膜行为的主要因素.研究同时发现,针对钙钛矿锰氧化物薄膜应变效应的界面结构设计、磁电耦合的微观物理机制、器件应用等方面的研究将成为今后的研究热点.     

可延展柔性光子/电子集成器件专辑·编者按

正可延展柔性光子/电子器件改变了传统器件的刚性物理形态,极大拓展了光子/电子器件的发展模式与应用空间,已成为信息器件发展的重要方向之一.本专辑中,作者们紧密围绕可延展柔性光子/电子器件,从力学、物理、材料、化学、信息等不同领域,以多学科深度交叉驱动发展的视角,深入研究了可延展柔性器件的物理原理、新型材料、设计理论及制备方法等,并对该领域的发展趋势进行了展望.形状记忆聚合物作为一类智能材料,具有形状可控、模量可调等特点,在柔性电子器件领域受到越来越广     

0-3型纳米复合材料P(VDF-TrFE)xFOM1-x磁电耦合效应

柔性电子元件的发展日新月异,其中有机薄膜因具有延展性、柔韧性、易制备等优点,使其在智能可穿戴柔性器件领域有着巨大的应用潜力.采用溶胶-凝胶法,利用有机聚合物P(VDF-TrFE)共聚物和有机磁性材料二茂铁间苯甲酰腙(FOM)在柔性聚酰亚胺(PI)衬底上成功制备了0-3型纳米复合薄膜.结构表征表明,FOM纳米颗粒均匀地分布在P(VDF-TrFE)基质中.纳米复合材料的晶体和微观结构取决于P(VDF-TrFE)和FOM的物质的量比,铁电和磁电响应受到FOM纳米粒子浓度的强烈影响.纳米复合薄膜的磁电耦合系数最高为15.1 mV/(cm·Oe)     

超宽禁带二维半导体材料与器件研究进展

超宽禁带二维半导体作为二维材料研究领域的前沿之一,在紧跟第三、四代半导体朝着大带隙、大功率方向发展的同时,也为集成电路往小体积、高集成度方向的探索提供了思路.根据晶体堆积是否为范德华层状结构,超宽禁带二维半导体在材料层面的研究内容一方面是将已有的或成熟的非层状材料通过各种限制手段将第三维度压制在纳米量级,另一方面则是探索新型的范德华层状材料通过生长或剥离的方式得到其单层或少层结构.从器件层面看,超宽禁带二维半导体无论是以独立形式还是两两组合叠成异质结,形成的器件大多都以探测紫外波段的电磁辐射为目的,进一步可以做成包括成像系统、数字通讯等在内的光学传感器.若是辅助以柔性衬底,那么二维材料将发挥天然的可弯折优势,被广泛应用到柔性场效应晶体管、柔性紫外探测器、显示器等可穿戴电子器件中.而当材料有对外界刺激(如光照)表现出“记忆”特性时,说明可以将材料用于类神经突触传感或神经网络学习.此外,超宽禁带二维半导体中具有超大带隙的部分材料是极具潜力的电介质,它们往往拥有远比氧化硅大的介电常数与击穿电压,在减薄器件体积的同时也优化了器件的性能.最后,少数超宽禁带二维半导体是许多材料制备过程中的衬底,它...     

功能高分子材料在柔性电子领域研究进展

柔性电子是基于柔性有机/无机功能材料、柔性/可延展基底并结合相应加工工艺得到的新型电子器件.与传统电子器件刚且硬的缺陷相比,柔性电子优秀的力学性能(柔性化和可拉伸等)使其更加适用于可穿戴电子、人机交互、软体机器人等尖端电子领域.自柔性电子起始阶段,高分子材料就被视为实现柔性电子技术走向应用的关键材料,例如柔性高分子基底材料、高分子界面改性材料、柔性高分子功能材料等.借助于高分子材料的优秀性能,半导体技术突破了传统材料的限制,实现了电子器件的柔性化,而且极大地拓展了柔性电子在生物医学、柔性显示屏、能量存储与转换器件以及人机交互等领域的应用.然而随着柔性电子技术的不断发展,现有的技术水平已经不能满足应用领域的苛刻需求,亟需在功能材料研究上获得突破.目前,研发用于柔性电子的新型功能高分子材料被视为解决这一问题的突破点之一.因此,本文基于本课题组的相关工作,综述了近期功能高分子材料在柔性电子领域的相关研究进展,基于柔性电子器件的组成角度以及加工工艺角度,从柔性电子中的三种关键材料(柔性基底材料、界面改性材料、柔性功能材料)出发,分析功能高分子材料在柔性电子领域的研究现状以及发展前景.     

纳米纸在绿色电子器件中的研究进展

 纳米纸是由纳米纤维素自组装形成的二维薄膜材料,具有高透明性和极低的表面粗糙度,是一种理想的柔性电子器件基底材料。与合成高分子基底材料相比,纳米纸可以生物降解,为绿色电子器件的制备提供了条件。本文梳理了纳米纸的制备工艺、纳米纸的特点及纳米纸在柔性绿色电子器件,尤其是场效应晶体管、能源器件和发光器件等方面的应用。针对纳米纸在大规模低成本制备、在柔性绿色电子器件中存在的问题进行了分析,并对纳米纸在生物传感中的应用进行了展望。     

应用于柔性有机电致发光器件的导电衬底材料研究进展

柔性有机电致发光器件(OLED)的制作是有机光电子领域内最具挑战性的课题之一.本文通过国内外近五年内柔性OLED器件衬底材料领域的最新研究成果,总结了柔性透明导电衬底材料的种类和制备技术,分析了各自的优缺点并提出了其未来的发展前景与趋势.     

棉秆基活性碳材料在柔性微型超级电容器中的应用

生物质碳材料具有高比表面积、轻质、可再生、价格低廉等优势,是一种很有前景的超级电容器的电极材料,随着电子器件的微型化,对储能器件的柔性也提出了一定的要求。为了满足人们对柔性电子器件日益增长的需求,解决储能器件小型化、柔性化等问题,本文利用氢氧化钾活化法,经过高温刻蚀棉花秸秆制备出具有多孔结构的碳材料,并将该材料制备成电极组装成微型超级电容器(MSCs),测试其电学性能。结果表明:当电流密度为0. 33 mA/cm时,比容量为32 mF/cm;弯曲直径在20 mm时,弯折2000次后仍有85%的电容保有量。本文以棉花秸秆为原材料制备MSCs的方法简单,且器件具有优异的电化学和机械性能,在未来柔性、小型电子器件领域具有广泛的应用前景。     

基于边缘剪切转移技术制备硅基柔性光波导

无机柔性光电子技术由于具有柔性、便携、大面积等优点而受到科研人员的广泛关注,并取得了长足的进展.制备无机柔性光电子器件的技术关键是将传统刚性衬底上的纳米"构筑单元"(Building Blocks)以一种可控的、精确的、具有超高对准度的方式集成在柔性基底上.本文针对"转印"(Transfer Printing)技术中纳米"构筑单元"向柔性衬底集成时的可控转移及确定性组装(Deterministic Assembly)等难题,提出了边缘剪切转移技术,实现了柔性硅纳米带阵列在柔性基底上的制备及确定性组装.结合悬臂梁模型及有限元模拟,得出悬空硅纳米带内部在边缘剪切转移过程中所产生的应力与其厚度、宽度之间的函数关系.此外,本文还研究了不同方向硅条带在边缘剪切转移的过程中所制备硅纳米带的边缘形貌,并优化初始硅条带的方向,得到边缘平整的硅纳米带.最终,利用该技术制备出柔性衬底上的硅基光波导.     

柔性显示基板材料研究进展

随着显示技术的不断发展,柔性显示以其质轻、可轻薄化、耐用和可收卷等优点,成为最具发展潜力的下一代显示技术. 柔性显示技术的实现除了要求现有的设计和制造工艺进行改进之外,更加对加工和使用过程中材料的性能提出了新的要求,其中,柔性基板作为柔性显示器件的重要组成部分,基板材料要求具有良好的光学透明度、柔韧性、热稳定性和阻水阻氧等特性,因此,开发出具有优异的综合性能的基板材料成为实现柔性显示的关键环节. 目前,可以作为柔性显示基板的材料包括聚合物基板、超薄玻璃基板、不锈钢基板、纸质基板和生物复合薄膜基板,以前3种最常用. 文中针对近年来柔性显示基板材料的研究状况,从光学透明度、热稳定性、机械性能、阻水阻氧性能和表面平坦性等方面对这5种基板材料的性能进行了比较,聚合物基板相较于超薄玻璃基板和不锈钢基板,不仅具有透明、柔性、质轻的优点,而且耐用性优良,被公认为具有非常广阔的应用前景,并对聚合物基板的研究进行了展望.     

Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors

Transparent electronic devices formed on flexible substrates are expected to meet emerging technological demands where silicon-based electronics cannot provide a solution. Examples of active flexible applications include paper displays and wearable computers. So far, mainly flexible devices based on hydrogenated amorphous silicon (a-Si:H) and organic semiconductors have been investigated. However, the performance of these devices has been insufficient for use as transistors in practical computers and current-driven organic light-emitting diode displays. Fabricating high-performance devices is challenging, owing to a trade-off between processing temperature and device performance. Here, we propose to solve this problem by using a novel semiconducting material--namely, a transparent amorphous oxide semiconductor from the In-Ga-Zn-O system (a-IGZO)--for the active channel in transparent thin-film transistors (TTFTs). The a-IGZO is deposited on polyethylene terephthalate at room temperature and exhibits Hall effect mobilities exceeding 10 cm2 V(-1) s(-1), which is an order of magnitude larger than for hydrogenated amorphous silicon. TTFTs fabricated on polyethylene terephthalate sheets exhibit saturation mobilities of 6-9 cm2 V(-1) s(-1), and device characteristics are stable during repetitive bending of the TTFT sheet.     

Polyacrylonitrile/Graphene-Based Coaxial Fiber-Shaped Supercapacitors

Supercapacitors have huge potential applications in the field of wearable electronic devices, such as flexible displays, flexible biosensors and implantable multimedia devices, due to their high-power density, fast charge-discharge rates, long cycling life, and relatively simple configuration. In this paper, we demonstrated hierarchically porous and continuous reduced graphene oxide-polyacrylonitrile@polyacrylonitrile(rGO-PAN@PAN) coaxial fibers with certain strength, excellent electrochemical performance through coaxial wet spinning and thermal reduction. Coaxial fibers are carbonized at high temperature and have a graded porous structure with a conductivity of 1 703 S/m. The areal specific capacitance of the supercapacitor assembled by polyvinyl alcohol/sulfuric acid(PVA/H_2SO_4) gel electrolyte is 11.56 mF/cm~2, and its energy density reaches 0.21 mW·h/cm~3, showing good electrochemical performance. Graphene-based coaxial fibers prepared by wet spinning have a great prospect of application in electronic devices due to their excellent properties.     

Patterning organic single-crystal transistor arrays

Field-effect transistors made of organic single crystals are ideal for studying the charge transport characteristics of organic semiconductor materials. Their outstanding device performance, relative to that of transistors made of organic thin films, makes them also attractive candidates for electronic applications such as active matrix displays and sensor arrays. These applications require minimal cross-talk between neighbouring devices. In the case of thin film systems, simple patterning of the active semiconductor layer minimizes cross-talk. But when using organic single crystals, the only approach currently available for creating arrays of separate devices is manual selection and placing of individual crystals-a process prohibitive for producing devices at high density and with reasonable throughput. In contrast, inorganic crystals have been grown in extended arrays, and efficient and large-area fabrication of silicon crystalline islands with high mobilities for electronic applications has been reported. Here we describe a method for effectively fabricating large arrays of single crystals of a wide range of organic semiconductor materials directly onto transistor source-drain electrodes. We find that film domains of octadecyltriethoxysilane microcontact-printed onto either clean Si/SiO(2) surfaces or flexible plastic provide control over the nucleation of vapour-grown organic single crystals. This allows us to fabricate large arrays of high-performance organic single-crystal field-effect transistors with mobilities as high as 2.4 cm(2) V(-1) s(-1) and on/off ratios greater than 10(7), and devices on flexible substrates that retain their performance after significant bending. These results suggest that our fabrication approach constitutes a promising step that might ultimately allow us to utilize high-performance organic single-crystal field-effect transistors for large-area electronics applications.     

Medium-scale carbon nanotube thin-film integrated circuits on flexible plastic substrates

The ability to form integrated circuits on flexible sheets of plastic enables attributes (for example conformal and flexible formats and lightweight and shock resistant construction) in electronic devices that are difficult or impossible to achieve with technologies that use semiconductor wafers or glass plates as substrates. Organic small-molecule and polymer-based materials represent the most widely explored types of semiconductors for such flexible circuitry. Although these materials and those that use films or nanostructures of inorganics have promise for certain applications, existing demonstrations of them in circuits on plastic indicate modest performance characteristics that might restrict the application possibilities. Here we report implementations of a comparatively high-performance carbon-based semiconductor consisting of sub-monolayer, random networks of single-walled carbon nanotubes to yield small- to medium-scale integrated digital circuits, composed of up to nearly 100 transistors on plastic substrates. Transistors in these integrated circuits have excellent properties: mobilities as high as 80 cm(2) V(-1) s(-1), subthreshold slopes as low as 140 m V dec(-1), operating voltages less than 5 V together with deterministic control over the threshold voltages, on/off ratios as high as 10(5), switching speeds in the kilohertz range even for coarse (approximately 100-microm) device geometries, and good mechanical flexibility-all with levels of uniformity and reproducibility that enable high-yield fabrication of integrated circuits. Theoretical calculations, in contexts ranging from heterogeneous percolative transport through the networks to compact models for the transistors to circuit level simulations, provide quantitative and predictive understanding of these systems. Taken together, these results suggest that sub-monolayer films of single-walled carbon nanotubes are attractive materials for flexible integrated circuits, with many potential areas of application in consumer and other areas of electronics.     

蛋白基柔性材料的介观重构及其光电子器件

自然界中的蛋白质材料具有天然丰度、多种化学成分、可调控的性能、优异的生物相容及可降解性能等特点,为柔性光电子器件的发展提供了新的机遇.然而,蛋白质化学稳定性差、机械柔性不可控等缺点使得传统加工技术难以应用在其表面,严重制约了其在柔性电子领域的应用.本文首先以丝蛋白和角蛋白为例介绍了天然蛋白材料的介观重构以及加工技术,阐述了天然蛋白质材料的多级网络结构与其物理性能的关系.在此基础上,侧重介绍它们在柔性传感、发光、晶体管及存储等器件中的应用,最后展望了蛋白基柔性材料在光电子器件发展中所面临的挑战以及发展机遇.     

Recent Progress for Gallium-Based Liquid Metal in Smart Wearable Textiles

The development of smart textiles has presentend new requirements for integrated devices that can be compatible with both conductivity and deformation. At room temperature, liquid metal presents both metallic properties and flexible properties, as well as low toxicity and biocompatible, which makes it more and more popular on the research of liquid metal based electronic devices. This review summarizes the basic physical properties, and the key points to be fabricated into fibers and fabrics including oxides and wettability. Meantime, the application in the field of textiles is presented. Liquid metal based electrical conductive fibers and flexible sensors can be fabricated mainly by injection and printing, as well as direct-writing for smart fabrics. Liquid metal can be integrated as functional components for smart wearable devices in the future by assembling the as-prepared fibers and fabrics with textile technology, such as twisting, sewing, knitting, and embroidering.     

有机场效应晶体管的研究与应用进展

有机场效应晶体管(Organic Field Effect Transistors,OFETs)是以有机半导体材料作为有源层的晶体管器件。和传统的无机半导体器件相比,由于其可应用于生产大面积柔性设备而被人们广泛的研究,在有机发光、有机光探测器、有机太阳能电池、压力传感器、有机存储设备、柔性平板显示、电子纸等众多领域具有潜在而广泛的应用前景。文中对OFET结构和工作原理做了简要介绍,之后重点讨论了最近几年来OFET中有机材料和绝缘体材料的发展状况,接着总结了OFET制备技术及其应用新领域,最后对OFET发展面临问题及应用前景做了归纳和展望。     

Preparation and supercapacitor performance of assembled graphene fiber and foam

Graphene-based materials have been full of vigor and tremendous potentiality for application in supercapacitors due to its variety of unique properties such as electronic properties, simple synthesis, etc. In developing new macroscopic nanostructured graphene materials for supercapacitors, considerable efforts have been made by the scientist including our research group. In this account, we describe our development of the construction of the assembled graphene especially fiber and foam, which have great potential in addressing the challenges in the synthesis of graphene-based electrode materials for supercapacitors. As the supercapacitors are reviewed in this article, they are accordant with the rapid development of flexible, lightweight, and wearable-electronic devices, overcoming the major some drawbacks of conventional bulk supercapacitors. We hope that this summary will benefit the further research of graphene-based materials for the applications in electrochemical energy storage devices and beyond.