Effect of a pi-bridging unit in triphenylamine-benzothiadiazole based donor acceptor chromophores for dye-sensitized solar cells

Yigit M. Z., Bilgili H., Sefer E., DEMİÇ Ş., ZAFER C., CAN M., ...More

ELECTROCHIMICA ACTA, vol.147, pp.617-625, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 147
  • Publication Date: 2014
  • Doi Number: 10.1016/j.electacta.2014.09.138
  • Journal Name: ELECTROCHIMICA ACTA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.617-625
  • Keywords: donor-acceptor dyes, pi-bridge effect, dye sensitized solar cells, ORGANIC-DYES, PHOTOVOLTAIC PERFORMANCES, RUTHENIUM SENSITIZERS, CONJUGATED POLYMERS, HIGH-EFFICIENCY, CARBAZOLE DYES, ALKYL CHAIN, GAP, ABSORPTION, THIOPHENES
  • Çanakkale Onsekiz Mart University Affiliated: Yes

Abstract

Two new metal free sensitizers based on triphenylamine-benzothiadiazole were synthesized and used in dye sensitized solar cells (DSSCs). Electrochemical and optical properties of the dyes were studied by cyclic voltammetry, UV-vis absorption and fluorescence spectroscopy. A red shift was observed by the attachment of a thiophene (MZ-259) instead of a phenylene (MZ-255) bridge. The reverse effect was observed in the electrochemical properties because of the more electron-donating thiophene incorporated into the cyanoacrylic acid as an anchoring-acceptor unit in this system resulted in a higher LUMO level. The charge distribution of the dyes was also proved by DFT calculations using the Spartan10 program with the parameters of B3LYP and 6-31G** basis set. Finally the photovoltaic performances were investigated under standard AM 1.5 illumination with a power of 100 mW/cm(2) using an ionic liquid based electrolyte. The power conversion efficiencies, eta, were increased from 3.16% to 3.81% by using thiophene instead of phenylene as a pi-bridge unit. (C) 2014 Elsevier Ltd. All rights reserved.