Effect of hydrogen radical annealing on SiN passivated solar cells

Remote plasma was used for PE-CVD of SiN films and it was found that hydrogen radical (H* ) annealing of c-Si cells with SiN films improved the efficiency of the cells. Cell efficiency of 21.8% was obtained by applying a SiN/SiO2 double-layer structure on the emitter of a PERL-type solar cell. It was found that the H* annealing has two effects: it reduces surface recombination velocity (SRV); and it degrades bulk-lifetime of p-type c-Si. To apply SiN practically, it is effective to use a rear n-floating or a triode structure. Reducing the exposed area of the p-type substrate by using n-type diffused layer increases the efficiency of solar cells.