Study On The Conductivity And The Performance Of Electrodeposited Cuprous Oxide Thin Films

The cuprous oxide (Cu2O) thin film is a kind of the potential material in the new energy applications, such as solar cell and photoelectrochemical water splitting. The tunable conductivity of Cu2O thin films is important in the research on new energy materials. The Cu2O thin films are electrodeposited on conductive glass in a cupric acetate solution. The conductivity of Cu2O thin films is controlled by tuning the concentration of anionic surfactant and the applied potential through the facile electrodeposition. The photoelectrochemical stability of Cu2O thin films is studied in an aqueous solution. It is concluded that:(1) The conductivity of electrodeposited Cu2O thin films is controlled by tuning the concentration of sodium dodecyl sulfate (SDS) in the cupric acetate solution with pH 4.93, the applied potential is -0.10 V (vs. Ag/AgCl/Sat. KCl). When the concentration of SDS is lower than or equal to 0.85 mM, the Cu2O thin films behave as the n-type semiconductor. When the concentration of SDS is higher than or equal to 1.70 mM, the Cu2O thin films behave as the p-type semiconductor, the acceptor concentration increases with the increase of SDS concentration in the plating solution for the p-type Cu2O films. The photoelectrochemical stability of Cu2O thin film electrodeposited with 2.50 mM SDS is good in 3 wt% NaCl solution.(2) The conductivity of electrodeposited Cu2O thin films is controlled by the applied potential in the cupric acetate solutions with 3.30 mM SDS. When the applied potential is positive than -0.05V (vs. Ag/AgCl/Sat. KCl), the Cu2O thin films behave as the n-type semiconductor. When the applied potential is negative than-0.10V (vs. Ag/AgCl/Sat. KCl), the Cu2O thin films behave as the p-type semiconductor, the acceptor concentration increases with the decrease of applied potential for the p-type Cu2O films. The metallic Cu appears in the p-type Cu2O films and the content of metallic Cu in the films increase with the decrease of applied potential.