Increase in the DSSC efficiency when using metal-coated carbon nanowall counter electrodes

Abstract

This research was conducted to improve the efficiency of dye-sensitized solar cells (DSSCs) using metal-layer-coated carbon nanowalls (CNWs) as counter electrodes. The CNWs were synthesized on a fluorine-doped tin-oxide (FTO) glass substrate in a microwave plasma-enhanced chemical vapor deposition (PECVD) system using methane (CH4), and the CNWS were sputter-coated with metal films several times by using an RF magnetron sputtering system and four-inch metal targets (Cu, W and Ni, separately). Then, the metal-layer-coated CNWs were used as counter electrodes for manufacturing the DSCCs. The vertical and the surface conditions of the metal-coated CNWs used as the DSCC electrodes were characterized by their electrical variations through field-emission scanning electron microscopy (FE-SEM) and Hall measurements. Their optical characteristics were analyzed using UV-Vis equipment, and the energy conversion efficiencies of the DSSCs manufactured using the metal-layer-coated CNWs as the counter electrodes were measured. The results confirmed that the efficiency improved when the W-coated CNW was used as the counter electrode.