Surface oxidized Ti3C2 MXene: Lead-free Cs2AgBiBr6 double perovskite solar cell efficiency enhanced by interfacial engineering.

• A bi-phasic titanium carbide MXene fabricated by thermal oxidation process. • TiO 2 -Ti 3 C 2 MXene material shows excellent light harvesting behaviour. • The MXene interfacial layer as improve the interfacial electron extraction. • The surface oxidized interfacial layer is achieved high 1.06 V oc and 1.31% PCE. In this study, thermal oxidation method is followed to prepare surface oxidized titanium carbide (TiO 2 -Ti 3 C 2) nanomaterial. Here, the formation of anatase phase TiO 2 nanoparticles over the surfaces of Ti 3 C 2 MXene is confirmed by UV–Vis, FT-IR, XRD and FE-SEM and HR-TEM studies. The TiO 2 -Ti 3 C 2 MXene acts an interfacial layer in double perovskite solar cell that exhibits high open circuit voltage (V oc of 1.01 V), short circuit current density (J sc of 2.64 mA/cm−2), fill factor (FF of 0.55) and power conversion efficiency (PCE of 1.35%) under ambient conditions. Hence, we suggest that this surface modified material will be useful for double perovskite photovoltaics applications. [ABSTRACT FROM AUTHOR]