基于石墨烯功函数调控的分子驱动能量转换器件

Harvesting energy from the environment using nanomaterials and nanotechnology is a hot topic because of increasing requirements of the nanodevices and nanosystems. In this project, we proposed a novel energy nanoconverter based on the work function modulation of graphene, which utilizing the potential inside graphene when the chemical environments around the device varies. To understand the key scientific problems including the scheme of work function adjustment, charge generation and transport process, adsorption-desorption behaviors of chemical molecules on graphene surface, comprehensive studies using first-principle calculation, band theory analysis and experiments will be carried out to thoroughly understand the working principles of the device. Surface work function measurement in the liquid or gas environment will be developed. Scientific model will be set to explain the electrical response of the device while exposing to chemical molecules unsymmetrically. Also, the microscale energy transfer and conversion principles will be explained. Principles to improve the performance of the device will be concluded in this project, and the concept will be applied to other two dimensional materials. This prototype device opens up a new window for the power supply of novel devices such as artificial skin, wearable devices etc. "Chemoelectric" effect proposed in this project will be another completely new concept for electricity conversion except for piezoelectric, thermoelectric and photovoltaic effect.

微纳电子器件的发展推动微电源技术的创新和变革，利用纳米材料开发能从日常环境中收集能量的微电源器件，已成为当今研究热点。本项目提出一种基于石墨烯功函数调控的新型分子驱动能量转换器件，当器件所处环境中化学分子状态改变时，石墨烯覆盖端和暴露端因功函数不同产生电势差，实现电能的获取。围绕石墨烯功函数调控机制、器件电荷产生及输运机制、化学分子在石墨烯表面的吸附脱附行为等关键科学问题，通过第一性原理计算、能带理论分析及实验研究相结合，揭示器件的工作原理。目标是发展液（气）体环境下石墨烯表面功函数的测试与计算方法，建立物理模型模拟器件在化学分子作用时的电学响应，研究微观尺度能量传递与转换机制，提出器件性能优化方案，推动相关原理在其他材料体系中取得应用。利用化学分子作用时石墨烯所产生的内部电势来实现电能收集，是继光电、压电、热电器件之后的又一全新理念，为人造皮肤、可穿戴等器件的电能供给提供了新的设计思路。

可穿戴、物联网、智慧城市等新兴产业的发展将推动微纳电子器件市场的迅速发展，牵引微电源产品的技术变革和不断创新。本项目提出一种区别于光电、压电、摩擦电等效应的一种新型分子驱动能量转换器件，研究了器件工作机理、合成工艺及对材料性能的要求，提出了下一步应用的方向。通过本项目的研究，证实以一维有序或二维半导体结构为工作单元，制备成半覆盖式器件，在极性有机分子作用下，器件的密封端和暴露端皆可产生电势差，外接电路可有电能输出。 . 项目发展了大尺寸石墨烯片层的制备和转移方法，成功制备了基于石墨烯的分子驱动能量转换器件；进一步用二维结构的半导体片层，如ZnO，MoS2等取代石墨烯，获得了更好的器件性能；器件工作机理研究证实，极性有机分子与器件相互作用时，在半导体表面形成双电层，而在其内部形成耗尽层。而在密封端，载流子浓度仍保持不变，因此密封端和暴露端就会产生电势差；利用半覆盖式器件的特性，将极性分子与器件的相互作用与光电效应结合，制备出了具有较高灵敏度和响应恢复速度的光电探测器件。