Fig. 1: Mechanism of n-type conductivity in the UV-treated ZnO film.
From: A Transparent Electrode Based on Solution-Processed ZnO for Organic Optoelectronic Devices
a Conductivity of the sol-gel-grown ZnO film (annealed at 160oC, thickness: 25 nm) plotted as a function of UV treatment time (emission wavelength of the UV lamp is 365 nm and the power of the lamp is 24 W). Before UV treatment, the conductivity is too low to be measurable by the four-point probe measurement setup used in this work. b Schematic representation for the selective trapping of the UV-generated holes by VO in ZnO. The trapping of holes leaves excess electrons in the CB, increasing the conductivity of ZnO.
