Highly transparent ZTO/Ag/ZTO multilayer electrode deposited by inline sputtering process for organic photovoltaic cells

Abstract

Indium-free ZTO/Ag/ZTO multilayer electrodes were deposited on glass by RF sputtering of zinc tin oxide (ZTO) and pulsed DC sputtering of silver (Ag) at room temperature in the specially designed Inline sputtering system and evaluated as transparent electrode of organic photovoltaic cells (OPVs). The dependence of the electrical and optical properties of ZTO films on the O2/Ar + O2 ratio was investigated. We fabricated the ZTO/Ag/ZTO multilayer electrode with a sheet resistance of 8.38–10.18 Ω sq−1 and average transmittance of 84.4–85.5% in the visible region (λ = 380–770 nm), which is compatible with commercial indium tin oxide (ITO). As an application, organic solar cells fabricated on the ZTO/Ag/ZTO multilayer electrodes with the conventional device architecture were compared with those on commercial ITO electrodes. The bulk heterojunction OPVs fabricated on the multilayer electrodes exhibited a short-circuit current (JSC) of 7.06 mA cm−2, a fill factor (FF) of 0.62, an open-circuit voltage of (VOC) of 0.64 V, and a power-conversion efficiency of 2.80%. This indicates that ZTO/Ag/ZTO multilayer electrode is a promising electrode scheme for bulk heterojunction organic photovoltaic cells (BHJ-OPVs).