Changes of properties of a Pt counter-electrode by ion-beam-assisted etching in a dye-sensitized solar cell

A dye-sensitized solar cell device with a structure of 0.45 cm² effective area of glass/FTO/blocking layer/TiO₂/N719 (dye)/electrolyte/100 run Pt/glass was employed. The 100 nnvthick Pt counter-electrode deposited with an RF sputter-coater, was etched to induce strain using ion-beam-assisted etching (IBAE) with Ar ions for 0-180 seconds. In order to improve the energy-conversion efficiency of a dye-sensitized solar-cell device. The photovoltaic properties (e.g., short-circuit current density, open-circuit voltage, fill factor, and energy-conversion efficiency) were characterized using a solar simulator and potentiostat. The strain and interface resistance of the Pt thin-film were examined using x-ray diffraction and impedance. The surface roughness and impurity of the Pt thin-film were examined using atomic-force microscopy and x-ray photoelectron spectroscopy. The measured energy-conversion efficiencies of the DSSC devices, at IBAE times of 0 and 60 seconds, were 5.06% and 5.50%, respectively. The increase in efficiency with IBAE time resulted from the compressive strain field caused by IBAE treatment. Above 60 seconds, the decrease in efficiency was due to residual Ar ions. Our results imply that the use of an IBAE-treated Pt-catalytic layer, with appropriate etch time, improves the efficiency of dye-sensitized solar cells.