Utilization of AZO/Au/AZO multilayer electrodes instead of FTO for perovskite solar cells

•Utilization of the AZO/Au/AZO multilayer electrodes for perovskite solar cells.•Low resistivity and high transmittance of AZO/Au/AZO deposited at room temperature via FTS.•Damage-free FTS method from the plasma for multilayer electrodes.•Achievement of high photo-conversion efficiency (~9.5%) using multilayer electrodes deposited via FTS.

Aluminum (3 at%)-doped ZnO (AZO)/Au/AZO multilayer films with low resistivity and high transmittance are in situ deposited at room temperature via facing-target sputtering for AZO and direct current (DC) sputtering for Au. The optical and electrical properties of multilayer films are compared with conventionally (on-axis) sputtered and facing-target sputtered (FTS) AZO films. The FTS samples show better crystallinity than that of on-axis sputtered samples, and the lowest value for resistivity is 7.9×10−5 Ω-cm at an Au layer thickness of 8 nm, which is compared with that of a conventional FTO electrode. The photo-conversion efficiencies (PCE) of the perovskite solar cells based on the AZO multilayer electrodes deposited via FTS and on-axis sputtering are 9.5% and 8.2%, respectively. Although the PCE of AZO multilayer-based-solar cells exhibit a lower efficiency than that of the FTO based-devices (~12.3%), the perovskite solar cell performance based on the FTS AZO multilayer electrodes is very attractive for applications to flexible planar-structured solar cells.