Improved photovoltaic performance of dye-sensitized solar cells by Au-ion implantation of titania film electrodes

Abstract

Plasmonic metal nanoparticles are known to work as light-harvesting antennae and to enhance photocurrents of photovoltaic cells. Therefore, in this work, the effect of gold (Au) ions distribution on the efficiency of dye sensitized solar cells (DSSCs) has been investigated. Thin films of TiO2 have been deposited on FTO glass substrates by the doctor tape method. Au ions were then implanted on these films with different fluence rates (i.e., 2 × 1014, 4 × 1014 and 6 × 1014 ions/cm2). XRD results confirmed that TiO2 is present in the anatase phase up to a 4 × 104 ions/cm2 fluence rate. At a 6 × 1014 ions/cm2 fluence rate, one peak of rutile is obtained which confirmed that the film has mixed phases of TiO2. UV results show that dye is adsorbed into all photoanodes. Maximum dye absorption is seen at a fluence rate of 4 × 1014 ions/cm2. The energy conversion efficiency of DSSC is highly dependent on the fluence rate of Au. At a fluence rate of 4 × 1014 ions/cm2, the cell has a high short circuit current density (JSC) of 7.21 mA/cm2, resulting in a high efficiency (×) of 2.92%. Impedance spectroscopy shows that the cell formed by Au ions fluence rate of 4 × 1014 ions/cm2 has a low recombination rate of electron/hole pairs.