Screen-printed metallization for p-Type poly-Si passivated contacts formed by LPCVD

We report on the metallization on passivating contacts by screen-printed metal pastes. The passivating contact consists of a thermal SiOx layer of 1 to 2 nm thickness, in combination with an in-situ boron doped low pressure chemical vapor deposited polysilicon layer of 300 nm thickness. After thermal annealing, SiNx deposition and contact firing, we find extremely low dark saturation current densities down to 1 fA/cm2. Using a commercially available high temperature fire through Ag paste, which is applied by conventional screen printing technology, we achieve a specific contact resistance c = 2 mOcm2. This makes the application interesting as rear side contact of industrial type high-efficiency p-type solar cells.