Design High Light Harvesting Device from Two-Dimension Materials: A DFT Investigation Principle

In this study, density functional theory (DFT) and time-dependent DFT (TD-DFT) methods were employed to investigate the geometrical, electronic, optical, and photovoltaic properties of graphene (G), silicon carbide (SiC), and graphene/hexagonal boron nitride (G/h-BN) nanostructures. Dimethyl sulfoxide (DMSO) was used as a solvent to enhance the electronic behavior of the systems. Key photovoltaic parameters such as open-circuit voltage (VOC), light harvesting efficiency (LHE), and the free energies of electron injection and regeneration were evaluated. Results revealed efficient electron injection from G, SiC, and G/h-BN into the conduction band of TiO₂. The HOMO levels of G and SiC were found above the I⁻/I₃⁻ redox potential, indicating potential limitations in electron regeneration; however, this was mitigated upon dissolution in DMSO. Additionally, DMSO improved optical absorption by red-shifting the UV–visible spectra. Overall, isolated G/h-BN and the DMSO-dissolved nanostructures show promise as sensitizers in dye-sensitized solar cells (DSSCs).