Single-junction flat-plate terrestrial solar cells are fundamentally limited to about 30% solar-to-electricity conversion efficiency, but multiple junctions and concentrated light make much higher efficiencies practically achievable. Until now, four-junction III–V concentrator solar cells have demonstrated the highest solar conversion efficiencies. Here, we demonstrate 47.1% solar conversion efficiency using a monolithic, series-connected, six-junction inverted metamorphic structure operated under the direct spectrum at 143 Suns concentration. When tuned to the global spectrum, a variation of this structure achieves a 1-Sun global efficiency of 39.2%. Nearly optimal bandgaps for six junctions were fabricated using alloys of III–V semiconductors. To develop these junctions, it was necessary to minimize threading dislocations in lattice-mismatched III–V alloys, prevent phase segregation in metastable quaternary III–V alloys and understand dopant diffusion in complex structures. Further reduction of the series resistance within this structure could realistically enable efficiencies over 50%.

从根本上讲，单结平板地面太阳能电池的太阳能-电转换效率大约为30％，但多结和聚光使实用效率更高。到目前为止，四结III–V聚光器太阳能电池表现出最高的太阳能转换效率。在这里，我们展示了使用单片，串联，六结倒置变质结构，在143 Suns浓度下在直接光谱下运行的太阳能转换效率为47.1％。当调整到全局频谱时，此结构的变体实现了1-Sun全局效率为39.2％。使用III–V半导体合金制造了六个结点的最佳最佳带隙。为了发展这些路口，必须使晶格不匹配的III–V合金中的螺纹位错最小化，防止亚稳的季铵–V合金中的相偏析，并了解掺杂剂在复杂结构中的扩散。在该结构内进一步减小串联电阻可以实际实现超过50％的效率。