Photochemical Reaction Patterns on Heterostructures of ZnO on Periodically Poled Lithium Niobate.

The internal electric field in LiNbO provides a driving force for heterogeneous photocatalytic reactions, where photoexcited holes or electrons can participate in redox reactions on positive (+c) and negative (-c) domain surfaces and at the domain boundaries. One method to characterize the surface chemical reactivity is to measure photoinduced Ag deposition by immersing the LiNbO in an aqueous AgNO solution and illuminating with above bandgap light. Reduction of Ag ions leads to the formation of Ag nanoparticles at the surface, and a high density of Ag nanoparticles indicates enhanced surface photochemical reactions.