Kinetically controlled catalytic formation of zinc oxide thin films at low temperature.

We developed a unique method to produce ZnO thin films by kinetically controlled catalytic hydrolysis of a molecular precursor at low temperature, operating in conjunction with the vectorial control of crystal growth. Using a system in which the diffusion of a volatile catalyst into a solution of molecular precursor of the metal oxide limits the rate of hydrolysis and establishes a gradient of catalyst concentration, we investigated the nucleation of textured nanoparticles at the gas-liquid interface and characterized their subsequent growth. Use of this slow diffusion method combined with prediction of molecular species using a partial charge model enables a higher level of organizational control than obtained in other low-temperature synthesis methods, without the use of organic molecules. Various metal oxides and their morphologies and chemical compositions can be tailored for specific applications using this relatively simple approach.