AlGaInP材料在高效多结太阳电池中的应用

Application of AlGaInP Material in High-Efficiency Multi-Junction Solar Cells

AlGaInP材料在III-V族化合物半导体中具有较高的带隙,是制备高效多结太阳电池中顶电池的理想材料之一。然而,在其金属有机气相外延（MOVPE）生长过程中的氧污染会形成深能级陷阱,这是影响材料质量的主要因素。探讨了影响AlGaInP材料带隙的几种工艺参数,包括Al含量、衬底偏角和生长温度。讨论了通过优化材料外延生长工艺和改进太阳电池结构,获得高质量AlGaInP子电池的几种技术途径,包括提高生长温度、生长速率和磷烷体积流量,以及采用Se作为发射区的n型掺杂剂和GaInP/AlGaInP异质结构。介绍了近年来AlGaInP材料在高效多结太阳电池领域的研究进展,包括正向晶格失配太阳电池、反向晶格失配太阳电池和半导体直接键合太阳电池,并对其未来的发展趋势进行了展望。

AlGaInP is one of the most desirable III-V compound semiconductor materials for the fabrication of the top cell of high-efficiency multi-junction solar cells due to its high band gap. However,oxygen contamination in the metal organic vapor phase epitaxy（ MOVPE） growth of AlGaInP material may result in the formation of deep-level traps,which is the main factor affecting the material quality.Several process parameters influencing the band gap of AlGaInP material are discussed,including aluminum content,substrate miscut angle and growth temperature. Several technical approaches for optimizing epitaxial growth parameters of the material and solar cell structures to obtain high quality AlGaInP subcells are discussed,including increasing growth temperature,growth rate and phosphine volume flow,and using Se as the n-type dopant in the emitter region and Ga In P/AlGaInP hetero-structures. The recent research progress of AlGaInP material applied in the field of high-efficiency multi-junction solar cells isintroduced,including upright metamorphic solar cells,inverted metamorphic solar cells and direct semiconductor bonded multi-junction solar cells. Besides,its future development trend is proposed.