Freshly etched porous silicon as counter electrode of dye sensitized solar cells

Abstract

Freshly etched porous silicon films are explored as the counter electrodes of TiO2-based dye-sensitised solar cells (DSSCs). The scanning electron microscope characterisations show that the 12-μm-thick porous silicon film has pores in the diameter of about 50 nm. Under AM1.5 illumination, the DSSCs with porous silicon electrodes exhibited an efficiency of 1.43% in contrast to the 5.5% of the control DSSC constructed with a platinum (Pt) counter electrode. The impedance study reveals that the porous silicon electrode has larger series and charge transfer resistances than those of the Pt counter electrode, while the cyclic voltammograms indicate that porous silicon exhibits moderate electrocatalytic activity. Our results have demonstrated that porous silicon films are helpful to be the counter electrodes of moderately efficient DSSCs.