固态型太阳能利用系统的微/纳尺度能量转换机理与调控方法研究

This research focuses on several critical thermal scientific issues of full spectrum utilization of solar energy in photovoltaic - thermoelectric hybrid devices: (1) the mechanism of high efficient photon capture and absorption; (2)the micro/nano scale energy transportation , conversion and control methods; (3) the energy matching mechanism and designing method of solid-state hybrid solar energy utilization devices. The mechanism of interaction between solar light and surface structure as well as the mechanism of photon absorption enhancement will be revealed in micro/nano scale. the method to achieve omnidirectional wide-spectrum enhanced absorption of solar cells is proposed. This research will establish the transportation and conversion theory of photo-generated carriers in solar cells, interpret the interaction mechanism and characterization between energy carriers and the surface structure, temperature of the solar cell. Furthermore, this research will also study the full spectrum photovoltaic - thermoelectric hybrid utilization, setup theoretical methods of energy matching and optimal designation based on photovoltaic - thermoelectric hybrid devices， develop new technologies of full spectrum utilization of solar energy. This research will study the capture, generation, transportation and conversion of the energy carriers such as photons, electrons and phonons, as well as reveal the interactions between energy carriers and materials. It will enrich the connotation of the energy science, and have significant academic and industrial worth for improving the efficient of solid-state solar energy devices.

本项目围绕基于光伏与热电转换耦合的太阳能高效全频谱利用中需要深入研究的若干共性关键热科学问题：（1）微/纳尺度太阳能高效捕获与吸收机理；（2）微/纳尺度能量输运、转换特性与调控方法；（3）复合固态型太阳能利用系统能量匹配机制。揭示微/纳尺度太阳能的强化吸收机理，提出太阳能宽光谱、等方性的强化吸收方法。阐明光伏电池表面微结构、电池温度对电池能量输运与转换过程的影响规律。诠释基于光伏与热电转换耦合的固态型太阳能利用系统的能量匹配机制，发展太阳能全光谱利用技术。从微/纳尺度系统地研究光子、电子和声子等能量载流子的捕获吸收、激发产生、迁移扩散、转化利用等过程，深入认识载流子与物质的相互作用机制，研究将丰富能源科学领域的内涵，对提高太阳能的能量利用效率、发展基于固态型能源器件的太阳能高效全光谱利用方法有着重要的学术意义和应用前景。

本项目系统地研究了微结构类型、材料属性和特征尺寸等对全光谱太阳能吸收特性的影响，建立了纳米颗粒强化吸收设计准则，围绕宽光谱、等方性等科学问题，提出了仿生及复合两种类型的表面微结构，阐明了结构形貌、材料属性和结构尺寸等因素对光子吸收特性的影响规律，揭示了散射效应、等离子激元、梯度折射率等强化吸收机理，解决了单一结构吸收波段受限的问题，建立了太阳能宽光谱、等方向的高效吸收方法。考虑微结构、温度效应和电学复合的影响，建立了描述光伏电池内部能量输运与转换过程的光电耦合模型，阐明了光电转换过程中的结构和温度效应；系统研究了不同种类光伏电池光生载流子输运与转换过程中的能量损耗，揭示了非本征能量损耗机制对光伏电池效率的影响规律，厘清了影响太阳能电池能量损耗的关键因素，为优化设计高效太阳能光伏电池提供了理论依据。考虑光伏和热电器件的温度效应和系统的热传递过程，建立了光伏-热电耦合系统的能量传递与转换模型，厘清了聚光比、光伏电池与热电器件种类、温度、冷却条件、接触热阻等因素对光伏-热电耦合系统效率与输出功率的影响规律，揭示了耦合系统的温度和能量匹配机制，建立了光伏-热电耦合系统的设计方法，提出了聚光光伏-相变-热电耦合的新方法，发展了太阳能全光谱高效利用技术。本项目丰富了能源科学的研究内涵，对提高太阳能的能量利用效率、发展太阳能全光谱高效利用技术具有重要的科学意义。