Micro–meso hierarchical porous carbon as low-cost counter electrode for dye-sensitized solar cells

Abstract

A micro–meso hierarchical porous carbon with low crystallinity was prepared by a combination of self-assembly and post activation and explored as a counter electrode in dye-sensitized solar cells. Pore structure analysis showed that the pristine mesopores were basically preserved during activation and the micropores were mainly generated within the mesopore wall. Due to its low crystallinity and unique pore-structure including both mesopores and micropores, hierarchical porous carbon exhibited a relatively higher electrocatalytic activity for triiodide reduction, as compared with the pristine mesoporous carbon electrode. This enhanced electrocatalytic activity is beneficial for improving the photovoltaic performance of dye-sensitized solar cells. Under irradiation of 100 mW cm −2, the dye-sensitized solar cell with hierarchical porous carbon counter electrode showed an overall conversion efficiency of 6.48%, which was 11.5% higher than that of the cell with pristine mesoporous carbon counter electrode.