摘要
湿度传感器与大气监测、工业生产和生物医疗等领域息息相关。随着科技的不断发展,人们对高性能湿度传感器的需求不断增加,这为湿度传感器行业的发展带来了前所未有的机遇和挑战,其中高性能湿敏材料的开发尤为关键。在诸多湿度传感器中,金属氧化物或金属氧化物/聚合物复合材料湿度传感器因其敏感元件选择的多样性、易于后加工处理和响应特性高等特点而受到广泛关注。与聚合物湿度传感器相比,陶瓷材料的合成过程更简便,响应也通常更为迅速,且聚合物的成本更低。近些年,新型纳米材料被广泛应用于湿度传感器领域,逐渐成为湿敏材料的主要发展方向及研究热点。零维和一维纳米碳质材料,如富勒烯、碳纳米管作为湿敏活性层制备的传感器通常具有大比表面积、可室温下工作、易于实现微型化、稳定性好等诸多优点,但它们的零维或一维结构与现有的平面电子器件加工工艺不相匹配。石墨烯是由sp2杂化的碳原子紧密排列构成的二维蜂巢晶格结构的单层石墨,其独特的二维结构适用于现有的平面电子器件加工工艺。石墨烯材料作为湿敏活性层受到研究者们的广泛关注是因为它具备诸多优异特性:(1)石墨烯的所有原子都在表面,具有超大的比表面积,原则上,石墨烯传感器的动态检测范围可以从单个分子到很高的浓度水平;(2)利用石墨烯的电学特性和力学特性可以很好地进行传感信号的转换;(3)金属、聚合物或其他修饰剂功能化的石墨烯能与特定分子发生相互作用,大大增强传感器的选择性;(4)石墨烯单晶可以制作四探针装置,从而能够避免接触电阻的影响,并大大提高灵敏度;(5)与其他纳米碳材料如碳纳米管相比,石墨烯和氧化石墨烯制备成本更低。本文综述了石墨烯湿敏性能及其应用的研究进展,着重讨论了本征石墨烯、氧化石墨烯和改性石墨烯的湿敏特性。文章最后分析了石墨烯基湿度传感器未来的发展方向和面临的挑战。
Humidity detection plays a very important role in the fields of atmospheric monitoring,industrial production and biomedical materials and devices.With the continuous development of science and technology,the increasing demands for high performances humidity sensor bring out unprecedented opportunity and challenge for humidity sensor manufacturing,in which the deve-lopment of high performance humidity-sensitive materials is of crucial significance.Humidity sensors based on various materials have been developed,including ceramic,semiconducting,and polymer materials.Among the rich variety of humidity sensors,metal oxide and metal oxide/polymer based sensors have received recent attention due to their diversified sensitive element choices,ease of posterior processing and higher response characteristics.Compared with polymer-based humidity sensors,the sensitive ceramics have facile synthesis process and short response time,while nevertheless higher production cost.In recent years,novel nanostructured materials have achieved wide application for humidity sensor,and gradually become the development trends and the hot spots of the humidity-sensitive materials.While serving as sensitive layer,the zero dimensional and one dimensional nanosized graphitic materials,e.g.fullerene,carbon nanotubes(CNTs)can impart lots of advantages such as large surface area,ease of miniaturization,room temperature workability,favorable stability to humidity sensors.But their zero dimensional or one dimensional structure is technologically unadaptable to the prevailing standard fabrication process for electronic devices.Graphene,a monolayer of sp 2 hybridized carbon atoms arranged in a honeycomb lattice with unique two dimensional(2D)structure,surmounts the technological obstacle for fullerene or CNTs,and the use of graphene as humidity-sensitive layer has drawn remarkable attention owing to its promising advantageous properties:Ⅰ.The theoretical dynamic detection range for graphene sensors may cover from a single molecule to a very high concentration level due to its extremely high surface to volume ratio with almost all the atoms exposed to the environment.Ⅱ.The electronic and mechanical properties of graphene greatly facilitate transduction of the sensing signal.Ⅲ.The sensing selectivity can be dramatically improved by adopting functionalized graphene which is incorporated with metals,polymers or other modifiers and can interact with specific molecules.Ⅳ.Graphene monocrystals can be used to fabricate four-probe devices,which can avoid the influence of contact resistance and improve sensitivity.Ⅴ.Graphene and graphene oxide are cheaper than other graphitic materials like CNTs.In this timely review,we render a vivid description of the recent advancement in humidity sensitivity features and sensor application of graphene and its derivatives,with emphases on the performance evolvement of intrinsic graphene,graphene oxides and modified graphene.Finally we make a concise discussion on the future challenges and perspectives of graphene-based humidity sensors.
作者
杨芳
张龙
余堃
齐天骄
官德斌
YANG Fang;ZHANG Long;YU Kun;QI Tianjiao;GUAN Debin(Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第17期2940-2948,共9页
Materials Reports
基金
国家自然科学基金(51402269)