Highly flexible, conductive and catalytic Pt networks as transparent counter electrodes for wearable dye-sensitized solar cells

We present a highly flexible dye-sensitized solar cell composed of TiO2 nanotube arrays (TNARs) as the photoanode and a transparent Pt network electrode as the counter electrode (CE). The network-structured Pt electrodes can be transferred onto arbitrary flexible substrates at room temperature and exhibit remarkable mechanical flexibility in bending and twisting tests. Up to 94% transmittance for Pt network electrodes can be obtained when the sheet resistances are over 170 Omega sq(-1). The CV and EIS analyses of the Pt networks reveal a comparable electrocatalytic behavior with the thermally deposited Pt particles on FTO glass. A photoelectric-conversion efficiency (PCE) of 3.82% was obtained by utilizing Pt networks as CEs in TNAR based DSSCs and maintained >90% PCE after 200 bending cycles. Such metal network based electrodes would be widely used not only in flexible solar cells but also in other wearable, lightweight electronic devices.