Roles of hydrogen atoms in p-type Poly-Si/SiOx passivation layer for crystalline silicon solar cell applications

Abstract

Cyclic dehydrogenation-rehydrogenation experiments have been performed on p-type poly-Si/SiO x stack to study the roles of hydrogen (H) atoms for crystalline silicon (c-Si) surface passivation. The effective lifetime of minority carriers is enhanced to 1.4 ms by the hydrogenation of hydrogen plasma treatment (HPT) at 300 °C. The dehydrogenation by thermal annealing at 450 °C decreases the lifetime to ∼0.6 ms, which is recovered by a consecutive HPT, underlining the c-Si surface passivation by H atoms diffused into the SiO x /c-Si interface. The lifetime recovery follows a stretched exponential function, indicating the dispersive nature of the p-type poly-Si/SiO x stack.