Synthesis and applications of new triphenylamine dyes with donor-donor-(bridge)-acceptor structure for organic dye-sensitized solar cells

Four novel asymmetric triphenylamine dyes configured with donor-donor-acceptor (D-D-A) and donor-donor-bridge-acceptor (D-D-pi-A) structures were synthesized and applied to organic dye-sensitized solar cells. The terminal methoxy group in the donor part and the furane-bridge unit contributed to the wider absorption region and enhanced electron life time, resulting in a higher photocurrent density (J(SC)), open-circuit voltage (V-OC), and overall conversion efficiency (eta). Among the synthesized dyes, the SK2-based DSSC showed the highest conversion efficiency of 5.57% (J(SC) = 10.41 mA cm(-2), V-OC = 729 mV, and FF = 0.73) caused by the synergetic effect of the methoxy group and the furane-bridge unit.