一种新型纤维状的光电转换器件

Effective photoelectric conversion plays a pivotal role in the progress and applications of electronic devices, and major attentions have been paid on solar cells traditionally. With the development of intellectronics, it is desired that electronics can be remotely controlled by light and simultaneously generate electricity, which, unluckily, has not been realized so far due to strict requirements for materials and structures. In this project, a novel strategy is proposed to integrate different functional materials in a simple and efficient way, through which a series of novel fiber-shaped flexible photoelectric conversion devices could be developed, generating programmed electricity under the remote control of light. The main designs are as follows: two kinds of composite fiber electrodes would be firstly fabricated by introducing photosensitive and charge storage polymers respectively into aligned carbon nanotube fibers, both of which are supposed to possess excellent mechanical, electrical and responsive performance as well. Then, two functional composite fiber electrodes would be twistedly assembled into a photoelectric conversion device. Under the light, the photosensitive composite fiber would deform and therefore electrostatic induction would occur in the charged composite fiber, consequently generating current. A systematic research would be carried on to summarize the influences of electrode compositions and structures, surfaces and interfaces as well as fabrication methods on photoelectric conversion performance. The mechanism and rules of how electrostatic induced charges transfer and distribute on interfaces of high curvature under photo-deformations would also be revealed. On this basis, a series of high performance fiber-shaped photoelectric conversion devices could be obtained and woven into textiles, pointing to a new direction of flexible optoelectronics.

有效实现光电转换对各类电子器件的发展和应用至关重要，传统上人们主要研究太阳能电池。随着智能电子学的发展，人们迫切希望通过光照遥控电子器件并同时实现发电，但因为对材料和结构的苛刻要求迄今尚未实现。本项目提出了一个简洁高效集成不同功能材料的新策略，发展出一类新型纤维状的柔性光电转换器件，实现光照遥控发电。主要研究思路：在取向碳纳米管纤维中分别引入光敏感和电荷储存功能的高分子，制备兼具优异力学、电学和响应性能的复合纤维电极；两根功能复合纤维电极缠绕组装制备光电转换器件；光照下，光敏感复合纤维发生形变，诱导储有电荷的复合纤维发生静电感应，产生电流。系统研究并总结出纤维电极组成和结构、表面和界面、构建方法等对光电转换性能的影响规律，揭示光致变形作用下静电感应电荷在高曲率界面传输和分布的机制与规律。在此基础上，获得一系列高性能光电纤维器件，并进一步将其编成织物，为柔性光电子学的发展提供了新方向。

实现能量有效转换，对各类电子器件的发展和应用至关重要。以光电转换为例，传统上主要研究太阳能电池，随着智能电子器件发展，人们希望同时实现发电和智能响应，因此对材料和器件结构提出了更高要求。因此，本项目提出将具有不同功能的多组分材料集成，利用能量传递实现光电转换的策略。具体来说，以光/热响应材料与碳纳米管复合制备了光致变形电极，以高分子驻极体与碳纳米管复合制备了静电感应电极，将具有光致变形作用和静电感应效应的纤维电极平行组装，发展了新型纤维状光电转换器件，在单一器件上实现了光能-机械能-电能的连续转换，并系统研究了材料组成和结构对器件性能的影响规律。发现高分子/取向碳纳米管复合材料具有优异的吸光和传热特性，且各向异性，能够高效实现光致变形和运动。为提高机械能-电能转化效率，发展了具有同轴结构的纤维状摩擦发电器件，能够在压力、拉伸、弯曲、震动等不同形式外力下发电，同时具有应力传感功能。基于上述思路和方法，通过设计螺旋膨胀微结构的复合电极，构建了纤维状压力传感器，只对压力响应，具有弯曲稳定性和空间分辨性；进一步将发光功能组分集成到纤维状传感器中，实现了压力传感的可视化。此外，还发展了新型电能转化器件，如低电压、高柔性的电致加热纤维和颜色动态可调的电致发光器件等。这些复合材料和电子器件有望为柔性电子学的发展提供新方向。.在本项目资助下，项目负责人以通讯作者发表论文16篇，包括1篇Nat. Biomed. Eng.、1篇Nat. Protoc.、1篇Nat. Rev. Mater.和1篇Adv. Mater.。申请中国发明专利5项，授权1项。担任Science Bulletin编委（2019-2020）、Advanced Functional Materials客座编辑（2019-2020）。入选上海市青年拔尖人才开发计划，获得2019年国家自然科学二等奖（第4完成人）。在项目执行期间，项目负责人协助指导毕业博士生2名、硕士生5名。