Deposition of zinc oxide photoelectrode using plasma enhanced chemical vapor deposition for dye-sensitized solar cells

We investigated the characteristics of zinc oxide (ZnO) photoelectrodes grown by plasma enhanced chemical vapor deposition. ZnO has many advantages, such as high binding energy, breakdown strength, cohesion, hardness, and electron mobility. On the F-doped SnO₂ (FTO) electrode, we deposited ZnO as a function of thickness, and we examined the thickness effect on the I-V, fill factor, open-circuit voltage, short-circuit current density, and especially the power conversion efficiency of the built in dye-sensitized solar cell. To study the thickness effect on the conduction and recombination of electrons in the ZnO electrode, we analyzed the alignment of grains, crystallinity, impedance, and cyclic I-V properties. The thickness of ZnO changed the electron diffusion length and recombination time. As a result, the maximum power conversion efficiency of 2.63% was obtained with a moderately thick (8.06 μm) ZnO.