Anatase TiO2 and ITO co-sputtered films for an indium-saving multicomponent electrode in organic solar cells

We report the characteristics of a Ti–In–Sn–O (Ti–ITO) multicomponent electrode prepared by co-sputtering of ITO and anatase TiO2 targets for reducing high-cost indium content in the anode layer of organic solar cells (OSCs). The dependence of electrical, optical, structural, and surface properties of the Ti–ITO multicomponent electrodes on the RF power was investigated in detail. The optimized Ti–ITO (80 W TiO2 co-sputtered ITO) electrode exhibited a low sheet resistance of 18.06 Ω/square, a high average optical transmittance of 80.61% and a root mean square roughness of 2.40 nm. The anatase TiO2 phase in the ITO matrix prevents the bixbyite structure from attaining the preferred orientation, producing a smooth surface of the Ti–ITO electrode. Moreover, the OSC with the optimized Ti–ITO anode showed an open circuit voltage (0.60 V), short circuit current (8.33 mA/cm2), fill factor (63.99%) and power conversion efficiency (3.18%) comparable to those of OSCs with a reference ITO electrode. This indicates that the Ti–ITO multicomponent electrode is a promising indium-saving multicomponent electrode that to reduces the indium content in ITO electrodes for low-cost OSCs.