High intensity UV radiation ozone treatment of nanocrystalline TiO2 layers for high efficiency of dye-sensitized solar cells

Abstract

We have improved the conversion efficiency of dye-sensitized solar cells (DSSCs) by using high intensity UV-ozone treatment on nanocrystalline TiO2 layers after sintering. The UV light sources used had powers of 1650W and 500W. UV-ozone treatment of nanocrystalline TiO2 layers was performed for 10min with a fixed distance between TiO2 layers and UV light source of about 3cm. Experimental results indicate that photocurrent and power conversion efficiency of cells increased when using high power 1650W and 500W UV-ozone treatment on TiO2 layers. The short circuit current density (Jsc) increased to 25.29±0.23mA/cm2 and 22.22±0.47mA/cm2, the open circuit voltage (Voc) to 0.73±0.02V and 0.74±0.02V, the fill factor (FF) to 0.66±0.01 and 0.71±0.03 and the power conversion efficiency to 11.95±0.45% and 11.12±0.28% respectively. The DSSCs were characterized for absorption dye, chemical structure on nanocrystalline TiO2 layer and electrochemical properties by UV–visible spectroscopy, XPS, XRD, contact angle measurement and impedance spectroscopy respectively.