Oliveira, KevinTeixeira, Jennifer P.Chen, Wei-ChaoLontchi Jioleo, JacksonOliveira, Antonio J. N.Caha, IhsanFrancis, Leonard DeepakFlandre, DenisEdoff, MarikaFernandes, Paulo A.Salome, Pedro M. P.2023-01-272023-01-272022http://hdl.handle.net/10400.22/21927Interface recombination in sub-µm optoelectronics has a major detrimental impact on devices’ performance, showing the need for tailored passivation strategies to reach a technological boost. In this work, SiOx passivation based substrates were developed and integrated into ultrathin Cu(In,Ga)Se2 (CIGS) solar cells. This study aims to understand the impact of a passivation strategy, which uses several SiOx layer thicknesses (3, 8, and 25 nm) integrated into high performance substrates (HPS). The experimental study is complemented with 3D Lumerical finite-difference time-domain (FDTD) and 2D Silvaco ATLAS optical and electrical simulations, respectively, to perform a decoupling of optical and electronic gains, allowing for a deep discussion on the impact of the SiOx layer thickness in the CIGS solar cell performance. This study shows that as the passivation layer thickness increases, a rise in parasitic losses is observed. Hence, a balance between beneficial passivation and optical effects with harmful architectural constraints defines a threshold thickness to attain the best solar cell performance. Analyzing their electrical parameters, the 8 nm novel SiOx based substrate achieved a light to power conversion efficiency value of 13.2 %, a 1.3 % absolute improvement over the conventional Mo substrate (without SiOx).engCu(In,Ga)Se2 (CIGS)Silicon oxide (SiOx)Rear passivation strategy,High performance substrateUltrathinOptical simulationsElectrical simulationsjournal article10.1109/JPHOTOV.2022.3165764