Difference in the influence of oxygen and nitrogen on the light induced effect

The influences of impurities such as oxygen and nitrogen on the light induced effect were studied. Although both oxygen and nitrogen had a strong influence on the light induced effect, there were large differences in their influences. The oxygen doped film had a longer time constant for the light induced change in the conductivity and gap state density than the nitrogen doped film. It was also found that oxygen was associated with the degradation of a‐Si solar cells. It is considered that the light induced effect is associated with the hole traps from the results of the degradation in n‐i‐n and p‐i‐p diodes. The degradation in a 2‐kW a‐Si power generating system was also analyzed.