To address the issue of parasitic absorption of UV light in the transparent conductive oxide (TCO) layer of flexible Cu(In,Ga)Se2 (CIGS) thin-film solar cells, researchers have integrated a CsPbBr3 perovskite nanocrystal-based luminescent down-shifting (LDS) layer. This layer is applied to CIGS solar cells fabricated on stainless steel foil. The CsPbBr3 nanocrystals absorb solar radiation at wavelengths shorter than 520 nm and re-emit photons at 532 nm. These down-shifted photons pass through the TCO layer without absorption and are instead absorbed by the CIGS layer, generating photocurrent. This innovation significantly improves the external quantum efficiency (EQE) of the CIGS solar cell in the UV range (300-390 nm) and enhances EQE between 500 and 1100 nm by reducing surface reflectance. As a result, the short circuit current density and power conversion efficiency of the flexible CIGS solar cells with the CsPbBr3 layer are improved by 4.5% compared to conventional cells without this layer.-Journal cover design by scapiens

https://pubs.rsc.org/en/content/articlelanding/2020/nr/c9nr06041c#!divAbstract