Electrodeposition and characterization of nanocrystalline cuprous oxide thin films on TiO_2 films

摘要

The grain size in cuprous oxide (Cu_2O) thin films is a key to improve the performance of solar application devices. In this paper, electrochemical deposition of nanocrystalline Cu_2O thin films on TiO_2 films coated on transparent conducting optically (TCO) glass substrates by cathodic reduction of cupric acetate has been investigated. The deposition kinetics of nanocrystalline Cu_2O thin films were studied and the parameters limiting the deposition of the films were determined. Pure Cu_2O deposited at bath temperature between 0 and 30 deg C produced spherically shaped grains with 40-50 nm diameters which have not been reported previously. The effect of pH was studied and a solution with a pH between 5.5 and 6 was found to be best. The effect of annealing on bulk structure, electrical resistivity, and optical absorption of nanocrystalline Cu_2O thin films was also studied and the results were discussed.