Metallisation of Boron‐Doped Polysilicon Layers by Screen Printed Silver Pastes

Abstract

In this work, we report on hole selective passivating contacts, which consist of a SiOx tunnel layer and an in situ boron‐doped 300 nm thick p+ polysilicon layer deposited by LPCVD. Using a SiNx:H capping layer, we show an extremely low dark saturation current density J0 of 1 fA cm−2 after contact firing. At the same time, we demonstrate that commercially available and screen‐printed fire through Ag pastes are capable of contacting the p+ polysilicon layer, with minimum contact resistance ρc = 2 mΩ cm2. We do find increased interface recombination below the metal contacts of around 250 fA cm−2, which represents a considerable advance compared to conventional screen printed metallisation on diffused junctions.