Sulfur-Functionalized Titanium Carbide Ti₃C₂T_x (MXene) Nanosheets Modified Light Absorbers for Ambient Fabrication of Sb₂S₃ Solar Cells

Modifying light-harvesting photoactive materials via doping and/or functionalization approaches is an effective approach for enhancing the efficiency and stability of solar cells. Herein, sulfur-functionalized two-dimensional (2D) transition-metal carbide (S-MXene) nanosheets are synthesized and introduced as doping agents into the Sb2S3 light absorbers for solar cells. Furthermore, Sb2S3 solar cells are fabricated in two different experimental environments including an inert gas (argon) and ambient conditions (air) using S-MXene as the dopant. Our theoretical calculations and experimental analysis revealed that the ambient air fabrication and incorporation of conductive S-MXene can lead to an increase in the charge transport of Sb2S3 solar cells as well as introduce a p-type doping effect. Moreover, the best-performing device with S-MXene fabricated in air exhibited significant enhancement (59.65%) in the performance with respect to the S-MXene-doped cells fabricated in a glovebox filled with an inert gas. This work not only introduces the possibility of ambient air fabrication of Sb2S3 solar cells but also opens an avenue toward the development of functionalized 2D dopants for Sb2S3 solar cells.