GeC/SiCx van der Waals heterojunction: Applications for water splitting and solar cell

We construct GeC/SiCx(x = 1,2,7) van der Waals heterojunctions to study the photoelectric properties. The first-principle calculations show that three heterojunctions have the Z-type band alignment by analyzing the charge transfer paths. The designed heterojunctions possess good optical absorption in the visible light region, suggesting potential applications in photocatalysis, solar cells, and other photovoltaic devices. It is found that GeC/SiC and GeC/SiC7 heterojunctions fulfill the requirements as photocatalysts from PH = 0 to PH = 14. Although the GeC/SiC2 heterojunction fulfills the requirements as a photocatalyst from PH = 6 to PH = 10, the GeC/SiC2-based solar cell presents excellent performance, whose power conversion efficiency reaches 24.6 % theoretically. The results demonstrate that GeC/SiCx (x = 1, 2, 7) is a potential candidate for photocatalytic and solar cell materials in the future.