Improvement in the power conversion efficiency of thiocyanate-free Ru(II) based dye sensitized solar cells by cosensitization with a metal-free dye

We have used a stepwise approach for cosensitization of a thiocyanate-free Ru(II) sensitizer with an organic dye (TDPP) for dye sensitized solar cells. The cosensitized SPS-01 + TDPP device showed enhanced V-oc and J(sc) relative to the individual dye sensitized solar cells. Upon the optimization, the device made of SPS-01 + TDPP dye yielded J(sc) = 13.7 mA cm(-2), V-oc = 0.70 V, FF = 0.72 and power conversion efficiency (PCE) = 6.90%. This performance is superior to that of either individual DSSC made from SPS-01 (PCE = 5.47%) and TDPP (PCE = 4.82%), fabricated under the same conditions.