Preparation of delafossite structure p-type transparent conducting CuAlO_2 thin films by sol-gel process

摘要

Highly transparent CuAlO_2 thin films (or powder) have been prepared with a simple sol-gel method, using Cu (NO_3)_2·3H_2O and Al(NO_3)_3·9H_2O as raw materials. XRD is used to confirm the delafossite crystal form of the CuAlO_2 films, and SEM is used to investigate their morphologies and thicknesses. In neutral electrolyte, Mott-Schottky plots are employed to analyze the flat band of the CuAlO_2 films, which is + 0.97 V vs. RHE, meanwhile, the valence band position and conduction band position are deduced. In the photoelectrochemical performance test, the CuAlO_2 thin films show obvious photo-cathodic features. Because of the extremely high transparency, the CuAlO_2 film has great potentials for solar cells and hole-transporting materials in photochemical cells.