表面等离激元增强GaAs基化合物太阳电池的光电转换效率

The III-V GaAs-based tandom solar cells have great potential especially in the aerospace field because of its high power-conversion efficiency, good antiradiation and spatial stability. However, in order to meet the bandgap and lattice matching, the material composition and preparation processes have to be strictly controlled, which is very difficult to achieve, leading to a rising cost and limited efficiency. The In0.3Ga0.7As film of high crystallinity has been successfully deposited on the GaAs film and we have studied the tuning and light-absorption enhancement mechanisms of the surface plasmon systematically. Therefore, we are planning to fabricate the GaAs/In0.3Ga0.7As dual-junction solar cells which is bandgap matching. By introducing the Al/Ag alloy nanoparticles, the power-conversion efficiency can be greatly improved due to the enhanced light-absorption which is induced by the strong localized electric filed and scattering effects induced by the localized surface plasmon of the metal nanoparticles. In conclusion, we are anticipating to fabricate the high-efficiency GaAs-based tandom solar cells, to illustrate mechanism of the surface plasmon enhanced efficiency of solar cells and lay a solid foundation for the wider application of the GaAs-based solar cells.

GaAs基多结化合物太阳电池，因其较高的光电转换效率，良好的抗辐照性能和空间稳定性等优势，在太空领域具有广泛的应用前景。然而GaAs基多结太阳电池对材料组分和制备工艺要求严格，且材料难以同时满足晶格和带隙匹配，导致电池制备成本高昂，同时限制了器件效率的进一步提高。我们已实现GaAs衬底上高质量In0.3Ga0.7As薄膜的外延生长，且对金属表面等离激元的调控和增强电池的光吸收机理有了深入研究。以此为基础在本项目中我们拟制备带隙匹配的GaAs/In0.3Ga0.7As双结太阳电池，同时在In0.3Ga0.7As子电池内引入Al/Ag金属纳米颗粒，利用表面等离激元强的局域电场及纳米颗粒强的散射作用增强太阳电池的光吸收，进一步提高器件的光电转换效率。通过实施该项目，我们期望制备出高效GaAs基多结太阳电池，进一步探明表面等离激元增强电池效率的机理，为GaAs基太阳电池的低成本大规模应用奠定基础。

针对目前GaAs基多结太阳电池器件结构复杂，同时对材料组分和制备工艺要求严格导致器件制备成本高昂的现状，本项目开展表面等离激元增强GaAs基化合物太阳电池的光电转换效率的研究。通过本项目的实施，我们通过调控生长工艺，实现了对低维纳米结构形貌和尺寸的灵活调控，设计并实现了等离激元增强的新型量子结构宽光谱中间带太阳电池，同时制备出新型高效III-V族/石墨烯肖特基结量子点中间带太阳电池，器件的效率达到国际较高水平。本项目的实施对降低GaAs基高效太阳电池的成本具有重要意义。