Cu(In,Ga)(S,Se)₂ (CIGS) solar cells show record efficiencies comparable to those of crystalline Si-based technologies. Their industrial module production costs are also comparable to those of Si photovoltaics in spite of their much lower production volume. However, the competitiveness of CIGS is compromised by the difference in performance between cell and module scales, known as the cell-to-module efficiency gap, which is significantly higher than in competing industrial photovoltaic technologies. In this Review, we quantify the main cell-to-module efficiency loss mechanisms and discuss the various strategies explored in academia and industry to reduce the efficiency gap: new transparent conductive oxides, hybrid modularization approaches and the use of wide-bandgap solar absorbers in the 1.4–1.5 eV range. To implement these strategies, research gaps relating to various device layers need to be filled.

铜（铟，镓）（硫，硒）₂（CIGS）太阳能电池的记录效率可与基于晶体硅的技术相媲美。尽管其工业模块的生产量要低得多，但其工业模块的生产成本也可与Si光伏相媲美。但是，CIGS的竞争力因电池和模块规模之间的性能差异而受损，这被称为电池与模块之间的效率差距，该差距明显高于竞争性工业光伏技术。在这篇综述中，我们量化了主要的电池到模块效率损失机制，并讨论了学术界和工业界为减少效率差距而探索的各种策略：新型透明导电氧化物，混合模块化方法以及宽带隙太阳能吸收器的使用。 1.4–1.5 eV范围。为了实施这些策略，