When the passivation films were calcined at
300 °C, they had an adequate amount of negative fixed charge density
(Qf = −3.1 × 1012 cm−2); however, a large amount of interface state
density (Dit=2.1 × 1012 eV−1 cm−2) suppresses the passivation effect
of the film. On the other hand, the films calcined at 600 °C showed enhanced
effective lifetime.