Computational mining of Janus Sc₂C-based MXenes for spintronic, photocatalytic, and solar cell applications

Two-dimensional (2D) Janus structures such as MoSSe and Janus graphene have grabbed global attention for their novel properties and interesting behaviors. In this study, via first-principles calculations, we have systematically explored the structural, electronic, and magnetic properties of Janus-functionalized Sc2CTT′ (T, T′ = H, O, OH, F, Cl). Interestingly, four Sc2COT′ were found to be ferrimagnetic half-metals with high predicted Curie temperatures, indicating their feasibility in spintronic applications. On the other hand, Sc2COHCl, Sc2CHCl, and Sc2CFCl are suitable photocatalysts for photocatalytic water splitting. In particular, Sc2COHCl with a bandgap of 0.99 eV is highlighted as an infrared light-driven photocatalyst. Sc2COHH, possessing an ideal direct band gap of 1.08 eV and noticeable optical absorption in the visible light region, is very promising as the donor material for solar cells. It is highlighted that the designed type II Sc2COHH/InS heterostructure solar cell could present a high power conversion efficiency of up to 21.04% by inducing effective photo-excited electron-hole separation, which is favorable for photodetection harvesting. We believe that our study will provide a feasible strategy for the design and application of MXenes.