Star-shaped carbazole derivative based efficient solid-state dye sensitized solar cell

Two new star-shaped carbazole molecules, including tri(9-(methoxyphenyl)carbazol-3-yl)amine named TMPCA having molecular glasses properties and hole transport properties were synthesized. Their thermal, optical, photophysical and electrochemical properties were studied. The carbazole based molecules exhibit high thermal stability with 5% weight loss temperatures over 480 degrees C with higher glass temperature transitions 164-175 degrees C than the classical spiro-OMeTAD reference molecule. Their optical band gaps (2.76 eV) are low enough not to hinder neither the absorption of the indoline sensitizer (D102) nor its photoexcitation and charge transfer. Solid state ionization potential (IPs) of TMPCA is well adapted to that of D102 and ensure a driving force Delta rG >0.2 eV for an efficient transfer and regeneration of the photo-oxidized dye. Solid-state dye sensitized solar cells ITO/TiO2/D102/T4MPCA/Au showed a power conversion efficiency of 2.23% with J(sc) of 8.85 mA cm(-2) under standard AM 1.5 simulated solar irradiation. (C) 2013 Elsevier B.V. All rights reserved.