Computational study of electrical and optical properties of t-GeC and g-GeC

Abstract

Two-dimensional (2D) materials, such as graphene, transition metal dichalcogenides, and metal–organic frameworks, have demonstrated enhanced catalytic performance and efficiency, owing to their large surface areas and tunable electronic properties. Among these, germanium carbide (GeC) monolayers, including graphitic GeC (g-GeC), 2D-GeC, and diamond-like GeC (d-GeC) have shown significant promise for photocatalytic applications. For instance, g-GeC has been explored as a cathode catalyst for fuel cells and lithium-oxygen batteries, while 2D-GeC has been studied for its synthetic methods, fundamental properties, and photocatalytic applications. Computational modeling suggests that germagraphene, a 2D form of GeC, may be effectively synthesized. In this work, we investigate the photocatalytic, electrical, and optical properties of two germagraphene monolayers, tetragonal GeC (t-GeC) and g-GeC, using density functional theory (DFT) calculations performed with the Wien2k code. The results reveal that both t-GeC and g-GeC exhibit direct band gaps along specific N vectors, as confirmed by their electronic properties. Furthermore, these materials demonstrate strong absorption of visible sunlight, making them suitable for solar-driven photocatalytic processes. Charge density analysis provides insights into the distribution of charge between Ge and C atoms, shedding light on their bonding and electronic interactions. These findings highlight the photocatalytic potential of germagraphene, positioning it as a promising material for applications in renewable energy technologies, such as solar energy harvesting and water splitting.