Patent ID: 7863080

Claim:
A process for making a tandem solar cell comprising the steps of: providing a ceramic substrate; providing a titanium-based alloy film on the ceramic substrate; providing an n + -p âˆ’ -p + laminate on the titanium-based alloy film by the steps of: using an atmospheric pressure chemical vapor deposition apparatus to deposit dichlorosilane and diborane on the titanium-based alloy film, thus causing the epitaxial growth of a p + type back surface field film on the titanium-based alloy film; raising the temperature in the atmospheric pressure chemical vapor deposition apparatus, thus causing the epitaxial growth of a p âˆ’ type light-soaking film on the p + type back surface field film; and conducting n + type deposition of phosphine on the p âˆ’ type light-soaking film, thus forming an n + type emitter on the p âˆ’ type light-soaking film; using a plasma-enhanced chemical vapor deposition apparatus providing SiCNO:Ar plasma for passivating the n + -p âˆ’ -p + laminate, thus forming an anti-reflection film of SiCN/SiO 2 on the n + type emitter; using potassium hydroxide solution for etching a portion of the n + -p âˆ’ -p + laminate in a patterned mask process; forming a p âˆ’ type ohmic contact on a portion of the titanium-based alloy film exposed from the n + -p âˆ’ -p + laminate; etching portions of the anti-reflection film in a patterned mask process; providing a titanium/palladium/silver alloy film on portions of the n + type emitter exposed from the anti-reflection film; annealing the titanium/palladium/silver alloy film in hydrogen; and forming an n âˆ’ type ohmic contact on the n + type emitter.