石墨烯与钛酸铋钠异质结构中的热-电能量转换

项目名称： 石墨烯与钛酸铋钠异质结构中的热-电能量转换

项目编号： No.51472160

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 杨俊和

作者单位： 上海理工大学

项目金额： 83万元

中文摘要： 本项目旨在构建一种基于石墨烯(G)/钛酸铋钠(BNT)基铁电薄膜异质结构的热电能量转换器件，将环境中废弃热能收集并转换为电能。器件基本结构为（G电极/BNT薄膜/改性石墨烯(m G)/G电极），其中mG为具有压电效应的单面修饰石墨烯，G为高导热、高导电、透明石墨烯电极。通过BNT薄膜成分、结构及热释电性质的优化、G电极电导/热导性质的优化及BNT薄膜与m G之间的协同作用综合提高器件热电转换效率。拟通过实验研究与模拟计算结合重点解决石墨烯的非对称掺杂及压电性质表征、BNT薄膜极化状态对石墨烯电子输运性质、压电性质的影响规律、BNT热释电效应与m G压电效应协同作用等关键问题。最终获得电能输出功率密度大于1 W /cm2的热释电发电器件，明晰相关物理机制，获得廉价、高效的器件制备方案，获得高效率、环保、适用范围广的热释电发电器件。

中文关键词： 热释电效应；石墨烯；钛酸铋钠；异质结构

英文摘要： This proposal aims at developing novel pyroelectricity based energy conversion materials that directly generate electricity from heat. The basic structure of the device is graphene/modified graphene/ferroelectrics/graphene (G-mG-F-G) heterostructures, where mG is one side modified graphene with pizoelectric effect. The graphene layers of these heterostructures are multilayer graphene sheets and act as transparent electrodes with extraordinary electrical and thermal conductivities. The modified graphene layer in the heterostructure is monolayer graphene sheet with un-symmetric coverage of Bi, Ba, Na, H, F adatoms or TiOx molecules. The effect of remnant polarization of the ferroelectric films on the density and mobility of the carriers of graphene electrodes will be investigated by first-principles calculation and Hall-effect measurements. Piezoelectricity of the modified graphene sheet in the G-mG-F-G heterostructure will be investigated by ab initio molecular dynamics simulation and scanning probe microscopy. The combination of computational and experimental investigations facilitates the designs of graphene-ferroelectrics heterostructures that could be used as practical pyroelectric generators with high current density and power density.In G-mG-F-G , the synergy of piezoelectric effect of the modified graphene layer and pyroelectric effect of the ferroelectric layers could result in the significantly enhanced thermal-to-electrical energy conversion.Through the optimization of graphene and ferroelectric layers, the output power density of the pyroelectric device can reach 1W/cm2. This research will provide an in-depth understanding on the effects of the interface between graphene and ferroelectrics on the piezoelectric and electrical properties of graphene sheets. This pioneering research in developing graphene-ferroelectric heterostructure could result in the practical applications of pyroelectric generators which are versatile, efficient and environmentally friendly in thermal-to-electrical energy conversion.

英文关键词： Pyroelectric effect;graphene;bismuth sodium titanate;heterostructures