Experiment of Drifting Mobilities of Holes and Electrons in Stabilized a-Se Film

The electrical properties of stabilized amorphous selenium typical of the material used in direct conversion x-ray imaging devices are reported. Carrier mobility was measured using time-of-flight (TOF) measurements to investigate the transport properties of holes and electrons in stabilized a-Se film. A laser beam with pulse duration of 5 ns and wavelength of 350nm was illuminated on the surface of a-Se with thickness of 400 . The photo induced signals of a-Se film as a function of time were measured. The measured transit times of hole and electron were about 8.73 and 229.17, respectively. The hole and electron drift mobilities decreases with increase of electric field up to 4V/. Above 4V/, the measured drift mobilities exhibited no observable dependence with respect to electric field. The experimental results showed that the hole and electron drifting mobility were 0.04584 V-1/s-1/ sand 0.00174 V-1/s-1/ at 10 V/.