Efficient organic sensitizers containing benzo[cd]indole: Effect of molecular isomerization for photovoltaic properties

Two isomeric organic dyes, JK-51 and JK-52 containing benzo[cd]indole were synthesized. Under standard global AM 1.5 solar condition, the JK-51 sensitized cell gave a short circuit photocurrent density of 17.43 mA/cm2, open circuit voltage of 0.680 V, and a fill factor of 0.71, corresponding to an overall conversion efficiency η of 8.42%. On the other hand, a solar-to-electric conversion efficiency of 6.88% was achieved with the isomeric dye JK-52. We found that the power conversion efficiency was shown to be quite sensitive to the isomeric configurations.