Solar cells sensitized by porphyrin dyes containing a substituted carbazole donor with synergistically extended absorption and suppressed the dye aggregation

To achieve high power conversion efficiency (PCE), three porphyrin sensitizers have been synthesized and explored to simultaneously enhance the photocurrent (J(sc)) and photovoltage (V-oc). On basis of the XW4, a benzothiadiazole (BTD) unit has been introduced to afford XW57 with the aim to extend the absorption wavelength and enhance the light harvesting ability. As a result, a J(sc) of 13.72 mA/cm(2) has been obtained for XW57, higher than that of XW4. On this basis, XW58 has been prepared by modifying the carbazole-based donor with two bulky dihexyloxyphenyl groups, and the superior anti-aggregation character raises the V-oc from 781 mV (XW4) to 844 mV. When both the BTD unit and the bulky groups are introduced to the acceptor and donor units, respectively, the resulting sensitizer XW59 exhibits a highest PCE value of 7.34% with synergistically enhanced J(sc) of 13.19 mA/cm(2) and V-oc of 793 mV. These results provide further insight into developing high performance dye-sensitized solar cells (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.