ITO/AZO Double-Layered Transparent Conducting Oxide Films for Organic Photovoltaic Cells

We investigated the electrical and optical properties of single-layered films of indium tin oxide (ITO) and aluminum-doped zinc oxide (AZO) as well as of double-layered ITO/AZO films. These transparent conducting oxide (TCO) films were deposited by sputtering. The ITO/AZO film (500/250 nm thick) had a transmittance slightly higher than that of the ITO film in the visible region, and exhibited slightly lower resistivity than that of the ITO film. These results suggested that photoelectric devices based on double-layered TCO films could be expected to exhibit higher photocurrents. To determine whether this was the case, we used the double-layered ITO/AZO film as the anode electrode in an organic photovoltaic (OPV) cell. The cell was found to exhibit better device performance than that of an OPV cell based on the single-layered ITO film.