Highly efficient and stable dye-sensitized solar cells from adding low melting point glass frits

TiO2 films were modified by adding a low melting point glass frit as a light scattering particle and applied to an anode electrode in dye-sensitized solar cells (DSSCs) to enhance the interconnection between TiO2 and fluorine doped transparent oxide. The optical properties, photovoltaic properties and microstructures of the photo electrodes were examined to determine the role of the low glass transition temperature (T-g) glass frit. Electrochemical impedance spectroscopy, the Brunauer-Emmett-Teller method and a scratch test were conducted to support the results. The DSSC with the TiO2 film containing 3 wt% low T-g frit showed optimal performance (5.1%, efficiency) compared to the TiO2-based one. The photocurrent density slightly decreased by adding 3 wt% low T-g frit due to its large size and non-conductivity. However, the decrease of current density was compensated for by the scattering effect, high surface area and low electron transfer impedance at the electrolyte-dye-TiO2 interface.