Toward BaSi 2 /Si Heterojunction Thin‐Film Solar Cells: Insights into Heterointerface Investigation, Barium Depletion, and Silicide‐Mediated Silicon Crystallization

The knowledge of the structural and compositional details of Si/BaSi 2 /Si heterostructure annealed at high temperature is a prerequisite for BaSi 2 application in heterojunction thin‐film solar cells. For this purpose, Si/BaSi 2 /Si heterostructures deposited by magnetron sputtering with different Si layer thickness are submitted to systematic structural and compositional characterizations. Results reveal a BaSi 2 /Si heterointerfacial variation caused by surface oxidation and Ba diffusion at the high temperature. Its effects on the optical and electrical properties of Si/BaSi 2 /Si heterostructure are presented. The outcomes of this work can be extended to BaSi 2 deposited by other techniques, and generate substantial advantages in BaSi 2 development ranging from improvement on material qualities and eventual deployment in thin‐film solar cells.