Thermal stability of amorphous silicon/silicon nitride stacks for passivating crystalline silicon solar cells

The thermal stability of amorphous silicon/silicon nitride double layer surface passivation of p-type and n+-type crystalline surfaces is investigated for different deposition temperatures of the silicon nitride capping layer. An increase from 300to400°C results in a significant improvement of the thermal stability of the surface passivation. The minimum surface recombination velocity achieved on p-type (1.5Ωcm) silicon wafers is 0.75±0.6cm∕s and remains at 10±0.5cm∕s after 30min annealing at 500°C.