Si-based solar cells have dominated the entire photovoltaic market, but remain suffering from low power conversion efficiency (PCE), partly because of the poor utilization of ultraviolet (UV) light. Europium(III) (Eu³⁺) complexes with organic ligands are capable of converting UV light into strong visible light, which makes them ideal light converter to increase the efficiency of solar cells. However, the low stability of such complexes seriously hampers their practical applications. In this work, we report a highly stable and luminescent ethylene-vinyl acetate (EVA) copolymer film consisting of a Eu³⁺ complex as a down-shift material, Eu (ND)₄CTAC (ND = 4-hydroxy-2-methyl-1,5-naphthyridine-3-carbonitrile, CTAC = hexadecyl trimethyl ammonium chloride), coating of which onto the surface of large area polycrystalline silicon solar cells (active area: 110 cm²) results in an increase of PCE from 15.06% to 15.57%. Remarkable stability of the luminescent film was also demonstrated under light-soaking test for 500 h, and no obvious luminescence degradation can be observed. The remarkable enhancement of the conversion efficiency by 0.51% absolute on such a large active area, together with the high stability of the luminescent film, demonstrates a prospect for the implementation of the films in photovoltaic industry.

硅基太阳能电池已经在整个光伏市场上占据了主导地位，但仍遭受着低功率转换效率（PCE）的困扰，部分原因是紫外线（UV）利用率不高。带有有机配体的⁺（III）（Eu ³⁺）配合物能够将紫外线转换为强可见光，这使其成为理想的光转换器，可以提高太阳能电池的效率。但是，这类配合物的低稳定性严重妨碍了它们的实际应用。在这项工作中，我们报告了由Eu ³⁺络合物作为降档材料Eu（ND）₄组成的高度稳定且发光的乙烯-乙酸乙烯酯（EVA）共聚物薄膜CTAC（ND = 4-羟基-2-甲基-1,5-萘啶-3-甲腈，CTAC =十六烷基三甲基氯化铵），涂在大面积多晶硅太阳能电池的表面上（有效面积：110 cm ²）导致PCE从15.06％增加到15.57％。在光浸泡500小时的情况下，也证明了发光膜具有显着的稳定性，并且没有观察到明显的发光降解。在如此大的有源区域上，转换效率显着提高了0.51％的绝对值，同时发光膜具有高稳定性，这证明了将膜用于光伏行业的前景。