Low surface reflectance by nanoimprinted texture with silicon-rich silicon nitride layer

Texture structure is usually fabricated on crystalline silicon (c-Si) solar cells to provide a low surface reflectance by an etching method such as alkali solution. In this study, we proposed nanoimprint lithography (NIL) as a fabrication process of the texture structure on the flat c-Si surface. The fabricated nanoimprinted texture which is a moth-eye structure by zinc oxide still has a high interface reflectance since the differences of the refractive index between the texture material and the c-Si substrate is large. We proposed an insertion of a Si-rich silicon nitride (SiN) layer between the texture and the substrate to solve this problem, and confirmed that the inserted Si-rich SiN shows remarkable benefits in terms of lowering the surface reflectance and providing a high carrier lifetime of the Si absorber, simultaneously.