Improving efficiency of organic solar cells by preparing aluminum-doped zinc oxide films by ion beam-assisted sputtering

This paper reports on the improvement of the efficiency of organic solar cells (OSCs) by using ion beam-assisted sputtering (IBAS) to synthesize the alumina-doped zinc oxide (AZO) anodes that are used therein. The anode voltage of the ion source and the substrate temperature during IBAS were varied. When the substrate temperature was 460 °C, increasing the anode voltage from 0 to 40 V increased the efficiency of the OSCs by ～50%. The optical, electrical, morphological, and interfacial properties of the AZO and organic layers were investigated. The improvement of OSCs was associated with an increase in the conductivity, FOM, surface work function of the AZO films, and a decrease in the contact resistance in AZO/CuPc interface.