Hamtaei, SarallahSarallahHamtaeiDebot, AliceAliceDebotScaffidi, RomainRomainScaffidiBrammertz, GuyGuyBrammertzCariou, EstelleEstelleCariouGarner, Sean M.Sean M.GarnerAguirre, AranzazuAranzazuAguirrePoortmans, JefJefPoortmansDale, Phillip J.Phillip J.DaleVermang, BartBartVermang2025-01-112025-01-1120252662-4443WOS:001390549900001https://imec-publications.be/handle/20.500.12860/45067Cu(In,Ga)(S,Se)2 absorbers with a bandgap in the near-infrared region are ideal candidates for a bottom cell in multi-junction solar cell architectures. In flexible and lightweight form factors, such devices could help power many applications through integrated solar cells. Here, we show the use of a two-step method to synthesize Cu(In,Ga)(S,Se)2, with a bandgap between 1.00 and 1.13 eV, on bendable ultra-thin glass, with minority carrier lifetimes approaching 100 ns, in a homogenous and repeatable fashion. We also report on conventional and alternative device fabrication methods with very low waste and toxicity footprints. Champion solar cells are fabricated based on absorbers with a graded bandgap between 1.05 and 1.1 eV, and an open circuit voltage approaching 600 mV. Our results show a way for scalable fabrication of all thin-film, flexible tandem solar cells, by means of industrially relevant processing steps in a low cost and sustainable fashion.Journal article10.1038/s43246-024-00706-xWOS:001390549900001CIGS SOLAR-CELLSDEPENDENT ADMITTANCE SPECTROSCOPYULTRATHIN GLASSPERFORMANCE