Effect of oxygen plasma treatment on performance of ZnO based dye sensitized solar cells

Abstract

In this paper we present impact of oxygen (O2) plasma treatment on zinc oxide (ZnO) films and the optimization of their performance as photoanodes in dye sensitized solar cells (DSSCs) employing the I−/I3− electrolyte and the N719 sensitizer. Detailed surface and structural characterization of the ZnO films were accomplished using XRD and scanning electron microscopy (SEM) analysis. XRD results revealed the synthesized ZnO material to be highly crystalline and exhibit hexagonal crystal structure. The surface morphology suggested the grains to appear in spherical shape and distributed randomly. The ZnO based DSSC without treatment of O2 plasma showed the short-circuit photocurrent density (Jsc) 0.40 mAcm−2, open-circuit voltage (Voc), 0.50 V and fill factor (FF) 0.47 and power conversion efficiency of 0.36%. After 15 min of O2 plasma treatment ZnO based DSSCs exhibited short-circuit photocurrent density (Jsc) 1.10 mAcm−2, open-circuit voltage (Voc), 0.42 V and fill factor (FF) 0.43 and enhanced power conversion efficiency of 0.76%.