Optimal synthesis of antimony-doped cuprous oxides for photoelectrochemical applications

摘要： We investigated the influence of Sb dopant concentration on the structural, electrical, and photoelectrochemical properties of the photocathode cuprous oxide (Cu2O) thin films. The photoabsorber p-type Cu2O films were prepared by electrodeposition in ionic electrolytes including copper sulfate and antimony sulfate at 333 K and pH=10. The small amount of Sb doping contributes to the fast Cu ion transport to the substrate and ion consumption; consequently, the p-type Cu2O with high crystalline quality can be reproducibly synthesized with high electrical stability. Among the various samples, the mole fraction of c(Sb)/[c(Cu)+c(Sb)] = 0.75 mol % exhibits the best electrical resistivity and improved transparency in the infrared region, which is involved with the fast overlap of the nuclei crystals under 5 nm from the high nuclei density. Additionally, the post-thermal annealed Sb-doped Cu2O sample reveals an enhanced photocurrent of ~0.65 mA/cm2 vs. RHE (reversible hydrogen electrode) without metal catalysts.