Figure 2: Temperature-dependent conductivity measurements under luminosity: (a) temperature dependence of I m a x , (b) I-V characteristics of the DNA film at 35 and 45°C. The insets show the increasing number of bubbles with a temperature, (c) irreversible I-V characteristics (at 30°C) of the DNA film which had been subjected to a high bias voltage at 80°C with opposing polarities. The insets show the assumed schematics of the bubble type defect movements inside the DNA molecules at 80°C.