激光辐照薄膜光伏电池的光-电-热-力耦合效应

For the laser beaming power system, the light-electricity conversion efficient of the photovoltaic cell determines that, large portion of the absorbed light energy would dissipate into heat, which leads to great temperature elevation in the cell. The light-electricity conversion always decreases with the increasing of the cell temperature and thereby bigger percentage of the absorbed light energy would change into heat and further enhance the temperature rising. The thermal strain resulted from the temperature elevation would influence the structure of the strained well and alter the light electricity conversion. Moreover, if the thermal stress due to the mismatch thermal expansion is too large, damage would be developed in the cell and partially release the cell strain, which would again influence the light-electricity conversion efficient of the photovoltaic cell. Moreover, the thermal choke accompanied with the damage in the cell would further increase the local temperature gradient as well as thermal stress, which would make the damage evolve, combine, propagate and even make the cell fail permanently. Therefore, we must describe mathematically the coupled optical, electrical, thermal and mechanical processes in the photovoltaic cell to design and optimize the procedure of light-electricity conversion. This project will carry through groups of laser irradiation tests on the typical multiple junction film photovoltaic cells with lasers of specific waves and, establish the mathematical model on the multiphysical responses of the photovoltaic cell. The coupled optical, electrical, thermal and mechanical effect in the process will be investigated and the coupled interaction mechanism on the conversions among light, electrical, thermal and elastic energy will be revealed to provide the theoretical base and experimental reference for evaluating and optimizing the laser beaming power system.

激光远距离能量传输系统的光电转换环节中，光伏电池的光电转换效率决定了，其吸收的激光光能很大一部分将耗散为热能，使光电池出现明显温升。温度升高通常会导致光电池的光电转换效率下降，从而使更多的光能变成热能、增大光电池温升。温升引起的热应变将通过影响应变量子阱结构和能带结构改变光电转换效率；光电池的热应力过高时会萌生损伤、部分释放光电池应变、进一步影响光电转换效率。材料损伤导致的热壅塞还会加剧局部温度梯度和热应力，促使损伤演化、汇聚、扩展并最终使光电池彻底失效。可见，给出激光辐照光伏电池的光-电-热-力耦合过程的数学描述，是光电转换环节设计和优化的前提。本项目将主要针对典型多结薄膜光伏电池，开展特定波段激光辐照等系列试验研究，建立光伏电池的激光辐照多物理场响应的数学模型，研究其中的光-电-热-力耦合效应，揭示光能、电能、热能和变形能转换中的耦合作用机制，为系统评估和优化提供理论基础和试验依据。

激光远距离能量传输系统的光电转换环节中，光伏电池的光电转换效率决定了，其吸收的激光光能很大一部分将耗散为热能，使光电池出现明显温升。温度升高通常会导致光电池的光电转换效率下降，从而使更多的光能变成热能、增大光电池温升。温升引起的热应变将通过影响应变量子阱结构和能带结构改变光电转换效率；光电池的热应力过高时会萌生损伤、部分释放光电池应变、进一步影响光电转换效率。材料损伤导致的热壅塞还会加剧局部温度梯度和热应力，促使损伤演化、汇聚、扩展并最终使光电池彻底失效。可见，给出激光辐照光伏电池的光-电-热-力耦合过程的数学描述，是光电转换环节设计和优化的前提。本项目主要针对典型多结薄膜光伏电池，开展了特定波段激光辐照等系列试验研究，建立了光伏电池的激光辐照多物理场响应的数学模型，研究了其中的光-电-热-力耦合效应，揭示了光能、电能、热能和变形能转换中的耦合作用机制，研究结果为系统评估和优化提供理论基础和试验依据。