THE BIAS-ANNEALING EFFECT ON A-SI-H PHOTODIODE

The bias-annealing effect has been investigated for a-Si:H photodiode. The characteristics of the photodiode have been successfully improved on mu tau-product. The characteristics of transient photocurrent are also improved by bias-annealing at 125 and 150 degrees C for around 10 0 h. The result of the transient photocurrent measurement reflects the density of states of the energy level at about 0.6 eV below the condu ction band. The thermal current density increases with increasing bias -annealing time. According to the results, it is suggested that the de nsity of stales around midgap decreases and that above the Fermi level increases by the bias-annealing treatment. The result indicates that the neutral-charged defect converts to the negative-charged defect in case of a positive correlation energy.