Photocrystallization of amorphous ZnO

Abstract

Structural changes stimulated by UV light irradiation for sol-gel-derived amorphous ZnO were investigated. Transformation of amorphous ZnO into the wurtzite phase was achieved by irradiation of 4.9 eV photons in air using a conventional low-pressure mercury lamp. On the other hand, the crystallization was not observed by UV irradiation in vacuum. Cleavage of the Zn–O network with electronic excitation and subsequent oxidation with activated oxygen species are deduced to be essential for the formation of the ordered structure from the amorphous phase.