Tóm tắt

Multilayered MoO3/Cu thin films were prepared by thermal evaporation in combination with the thermalrntreatments. As-deposited multilayers are amorphous structure. With the increase of temperature, Mo4O11 phasernforms in the thin films without copper while MoO2 phase with the weak reduced molybdenum oxide appears inrnthe copper-containing thin films. After annealing at the temperature higher than 450 ◦C predominant MoO2rnappears in the multilayered MoO3/Cu thin films. Meanwhile, CuO and Cu2O are also present in the thin films.rnThe formation mechanism of reduced molybdenum suboxide can be explained by the oxygen-vacancy generationrnreaction or the reduction of MoO3 to MoO3-x via the inter-diffusion at the MoO3/Cu interfaces. The band gaps andrnconductivity activation energies of multilayered MoO3/Cu thin films decrease as the annealing temperaturernincreases, in which the smallest band gap of ~2.05 eV and activation energy of ~0.02 eV for the MoO2 thin filmsrnare found. Our results open a new road to broaden the application of reduced molybdenum suboxides as a backrncontact material for CdTe solar cells.