Ru employed as Counter Electrode for TCO-less Dye Sensitized Solar Cells

Abstract

A TCO-less ruthenium (Ru) catalytic layer on glass substrate instead of conventional Ru/TCO/glass substrate was assessed as counter electrode (CE) material in dye sensitized solar cells (DSSCs) by examining the effect of the Ru thickness on the DSSC performance. Ru films with different thicknesses (34, 46, 69, and 90 nm) were deposited by atomic layer deposition (ALD) on glass substrates to replace both existing catalyst and electrode layer. In order to make our comparison, we also prepared an Ru catalytic layer by a similar method on FTO/glass substrate. Finally, we prepared the 0.45 cm(2) DSSC device the properties of the DSSCs were examined by cyclic voltammetry (CV), impedance spectroscopy (EIS), and current-voltage (I-V) method. CV measurementsrevealed an increase in catalytic activity with increasing film thickness. The charge transfer resistance at the interface between the electrolyte and Rudecreased with increasing Ru thickness. I-V resultsshowed that the energy conversion efficiency increased up to 1.96%. Our results imply that TCO-less Ru/glass might perform as both catalyst and electrode layer when it is used in counter electrodes in DSSCs.