太阳光驱动纳米发电机用一维铁电材料的光伏机理研究

The invention of piezoelectric nanogenerator lays the significant foundation for the realization of micro/nano-systems. However, the nanogenerator requires an ambient mechanical force. Can we use solar energy as the motive power for nanogenerator? The anomalous photovoltaic effect in ferroelectrics makes it possible to use low-dimensional ferroelectrics for the forever dynamoelectric nanogenerator driven by sunlight. Comparing with the films, the nanowires have many characteristics such as easily single-crystallizing, excellent orientation, strong optical absorption, and etc., therefore ferroelectric nanowires are convenient for use in nanogenerator. However, there are obvious differences between the ferroelectric domain configuration, ferroelectricity and electrical conductivity of nanowire and that of ferroelectric film. Moreover, the effect of interface between the electrodes and ferroelectrics is weaker in ferroelectric nanowires. Consequently, we can deduce that there are obvious differences between the generation mechanism, separation mechanism and transportation mechanism of the charge carriers in ferroelectric nanowires than that in ferroelectric films. Furthermore, the mechanisms of ferroelectric nanowires are further close to the intrinsic photovoltaic mechanism of ferroelectrics. In this project, the relation between the microstructures of bismuth ferrite nanowires and the technological parameters of hydrothermal method will be investigated, and then the manipulation methods of the microstructures of ferroelectric nanowires will be found out. In single-crystalline bismuth ferrite nanowires the relation between the optical absorbability and band gap and the microstructures, the relation between the photovoltaic property and the domain configuration and ferroelectricity, the relation between the photovoltaic property and the conductivity of tiny region will be investigated, and then the generation mechanism, separation mechanism and transportation mechanism of ferroelectric nanowires will be revealed. As a result, the manipulation methods and mechanism of photovoltaic property of ferroelectric nanowires will be clarified. These researching results will provide a new train of thought and new bases for the researches on the nanogenerator and the intrinsic photovoltaic mechanism of ferroelectrics.

压电纳米发电机为微/纳米系统的实现奠定了重要基础，但需外界机械力作用。能否将太阳能作为纳米发电机的动力？铁电材料的反常光生伏打效应使低维铁电材料用于太阳光驱动（永久供电型）纳米发电机成为可能。而纳米线比薄膜更易单晶化、方向性好、光吸收强，因此铁电纳米线更适于作纳米发电机。但其畴结构、铁电性、导电性等与铁电薄膜存在显著差异且电极界面效应较弱，我们推测在铁电纳米线中载流子的产生、分离和输运机制与铁电薄膜有明显区别且更接近于铁电光伏本征机理。本项目通过研究铁酸铋纳米线微结构与水热法工艺的关系，掌握铁电纳米线微结构调控方法；通过研究单晶铁酸铋纳米线光吸收性能和带隙与微结构的关系、光伏性能与畴结构和铁电性的关系、光伏性能与微区导电性的关系，揭示铁电纳米线中光生载流子产生、分离、输运的机制，从而掌握铁电纳米线光伏性能调控方法，弄清其光伏形成机理，为纳米发电机和铁电光伏本征机理的研究提供新思路和新依据。

压电纳米发电机为微/纳米系统的实现奠定了重要基础，但需外界机械力作用。本项目提出太阳光驱动的纳米发电机，它不仅可对航空航天等领域的纳米器件长久持续供电，而且有助于推动航空航天系统的微型化、纳米化（如纳米卫星、纳米飞船等）。铁电材料的反常光生伏打效应使低维铁电材料用于太阳光驱动（永久供电型）纳米发电机成为可能。欲研制基于窄带隙铁电纳米线的太阳光驱动纳米发电机这一新型器件，核心问题是掌握这类纳米线的光伏性能调控方法及机理。.按照计划重点研究了铁酸铋纳米线的结构调控和铁电纳米线中光生载流子形成机制、分离机制、输运机制，并开展了计划外的铜铟镓硒和硒化锑半导体光伏薄膜研究以及太阳能电池用银浆制备。.采用水热法、模板法、微波法制备出铁酸铋纳米线，掌握了调控铁电纳米线微结构的方法，为铁电纳米线的光伏性能调控及机理研究奠定了材料基础。采用扫描探针显微镜等手段表征了铁酸铋纳米线微区结构和性能，揭示了铁电纳米线中光生载流子形成机制、分离机制、输运机制，为铁电纳米线的光伏性能调控及铁电光伏纳米发电机奠定基础。掌握了太阳能电池用银浆的制备方法，为制作光伏纳米发电机和太阳能电池奠定了电极基础。掌握了铜铟镓硒和硒化锑两种半导体薄膜光伏性能的工艺、组成调控方法，探索了光伏纳米发电机用新材料体系。.发表SCI论文6篇，接收SCI论文1篇，授权发明专利3件，培养青年科技骨干2名。