Molecular engineering of organic sensitizers containing indole moiety for dye-sensitized solar cells

Abstract

Three organic dyes, JK-77, JK-78, and JK-79 containing indole unit are designed and synthesized. Nanocrystalline TiO2 dye-sensitized solar cells were fabricated using these dyes. Under standard global AM 1.5 solar condition, the JK-79 sensitized solar cell gave a short circuit photocurrent density of 13.62 mA cm(-2), open-circuit voltage of 0.705 V, and a fill factor of 0.74, corresponding to an overall conversion efficiency eta of 7.18%. We found that the eta of JK-79 was higher than those of other two cells due to the higher V-oc. The improved V, value is attributed to the suppression of dark current owing to the blocking effect of a long alkyl chain. (C) 2008 Elsevier Ltd. All rights reserved.