Porous carbon layers for counter electrodes in dye-sensitized solar cells: Recent advances and a new screen-printing method

We review the recent literature on carbon catalyst layers for dye-sensitized solar cells (DSCs), and then report an improved fabrication method for screen-printed carbon counter electrodes. The carbon-printing ink was prepared by mixing carbon black, TiO2 nanoparticles, alpha-terpineol, and ethyl cellulose using a mortar, an ultrasonic homogenizer, and a rotary evaporator. Scanning electron microscopy (SEM) showed that the resulting screen-printed carbon layers were flatter and smoother at nano- and micro-scales than a carbon layer prepared using water-based ink. The photovoltaic performance of the screen-printed catalyst layers was similar to the photoenergy conversion of platinum counter electrodes. The highest cell efficiency with a carbon counter electrode was 7.11 % at a light intensity of 100 mW cm(-2).