Design and development of electronic- and micro-structures for multi-functional working electrodes in dye-sensitized solar cells

Abstract

This paper outlines a new strategy to optimize the performance of electrodes in dye-sensitized solar cells (DSSCs), through the engineering of electronic structures in conjunction with the micro-structures of the devices. We propose a simple hydrolysis method for the fabrication of a family of quasi-core–shell TiO2 (hydrolysis)/PbS composites for working electrodes. Measurements confirm a shift in absorption from the UV to visible range. We also measured cell performance, including short-circuit photocurrent, open-circuit photovoltage, and the power conversion efficiency (η) of DSSCs. The obtained η of DSSC (6.05%) with a TiO2 (P-25)/TiO2 (hydrolysis)+0.005M PbS electrode is substantially higher than that of the conventional DSSC (5.11%) with a TiO2 (P-25) electrode, due to improved p–n junctions, light-scattering, and light absorption. Finally, the shell of TiO2 (hydrolysis) protected the core of PbS from the corrosive effects of electrolytes, thereby prolonging the life span of the DSSC. This novel approach to electrode design could lead to advances in DSSC as well as other energy applications including photo-catalysis technology.