Firing-stable PassDop passivation for screen printed n-type PERL solar cells based on a-SiNx:P

Abstract Rear side passivation and local back surface field formation are two of the main technological challenges for n -type PERL silicon solar cells. A promising approach is the PassDop process. This process combines a phosphorous doped passivation layer deposited on the rear side with a subsequent laser process to create both a local contact opening as well as a local back surface field. In this paper we introduce a new layer system based on doped amorphous silicon nitride (the fPassDop process) which is able to passivate the n -type surface after a firing step as typically used for screen printed contacts. After the firing step, an effective recombination velocity fPassDop process is applied to small area solar cells achieving a conversion efficiency of 21.3% (675 mV V oc ). Additionally, we fabricated large area n -type solar cells with screen printed front side contacts achieving 20.1% efficiency and V oc of 668 mV.