US Patent 7892953 Method for making multi-crystalline film of solar cell

A method is disclosed to make a multi-crystalline silicon film of a solar cell. The method includes the step of providing a ceramic substrate, the step of providing a titanium-based film on the ceramic substrate, the step of providing a p+-type back surface field layer on the titanium-based film, the step of providing a p−-type light-soaking layer on the p+-type back surface field layer and the step of conducting n+-type diffusive deposition of phosphine on the p−-type light-soaking layer based on atmospheric pressure chemical vapor deposition, thus forming an n+-type emitter on the p−-type light-soaking layer.