MOBILITIES OF HOLES AND ELECTRONS IN IODINE SINGLE CRYSTALS

The mobilities were measured by the observation of the transit times of optically generated current pulses moving across the crystal under space-charge limited conditions. The majority carriers were holes at room temperature. These had a mobility, measured in the b-direction, which varied as exp -ΔE/kT with ΔE = 0.08eV over the temperature range 190-280°K. The mobility was 0.66 cm2/Vsec at 293°K. The transit of electrons was also observed in the temperature range 140-260°K. The electron mobility varied as T-0.8 over this range, with μe = 0.6 cm2/Vsec at 250°K. The holes created by light absorption in either of the two main iodine absorption bands have essentially the same mobility, indicating hole transport in a common valence band. © 1969.