(92e) Chemical Vapor Deposition Reactor Design for Copper Oxide Films Used in Photoelectrochemical Hydrogen Production Applications

Copper oxide films have been shown to be a promising electrode material for the direct production of hydrogen by the photoelectrochemical (PEC) decomposition of water. In this paper, we will present a chemical vapor deposition (CVD) process for depositing thin films of copper oxide. CVD is a desirable means of creating these films from both manufacturing and materials development standpoints. In terms of the former, CVD processes can deposit thin films relatively rapidly and conformally over very large substrates; the interdependence of gas phase reactant transport and gas/surface reactions creates opportunities for manipulating film composition and microstructure for optimizing the PEC performance of the deposited materials.

In this paper, we will discuss our work in developing a hot-wall tubular CVD reactor for copper oxide film deposition using a solid-source copper precursor and oxygen. Initial deposition results have shown that the reactor can reliably deposit solid polycrystalline cuprous oxide films and porous cupric oxide films, the latter being the more promising PEC material. Unusual spatial patters observed in the film composition prompted the development of a physically based mathematical model of the CVD process consisting of descriptions of gas phase chemical species transport combined with model elements corresponding to the gas phase and surface reactions. Initial results of this modeling work and its role in understanding and optimizing the deposition process will be presented. Progress in characterizing the CuO films with regard to PEC activity also will be presented.