Influence of ferroelectricity on the photoelectric effect of LiNbO3

Abstract

A comparison between domain dependent photochemical and photoelectric cation reduction in LiNbO3 is presented. The reduction in photoelectric threshold for LiNbO3 due to the depolarization field allows UV irradiation to produce free electrons that can participate in photochemical reduction in silver nitrate. This is in addition to domain directed photophysics, where influences on the space charge layer due to the internal dipole of a ferroelectric determine the carrier at the surface. We show that the interaction of photoelectric and domain dependent influences is observed in LiNbO3 due to the low electron affinity (∼1-1.5 eV) and band bending (0.3-0.8 eV). © 2008 American Institute of Physics.