Abstract
New porphyrin sensitizers based on donor- pi -acceptor (D- pi -A) approach have been designed, synthesized, characterized by various spectroscopic techniques and their photovoltaic properties explored. N,N'-Diphenylamine acts as donor, the porphyrin is the pi -spacer, and either carboxylic acid or cyanoacryclic acid acts as acceptor. All compounds were characterized by using super(1)HNMR spectroscopy, ESI-MS, UV-visible emission spectroscopies as well as electrochemical methods. The presence of aromatic groups between porphyrin pi -plane and acceptor group push the absorption of both Soret and Q-bands of porphyrin towards the red region. The electrochemical properties suggests that LUMO of these sensitizers above the TiO sub(2) conduction band. Finally, the device was fabricated using liquid redox electrolyte (I super(-)/I sub(3) super(-)) and its efficiency was compared with that of a leading sensitizer. Rooftop ready: New porphyrin sensitizers based on a donor- pi -acceptor approach have been designed, synthesized, and characterized by various spectroscopic techniques and their photovoltaic properties were explored. The electrochemical properties suggest that the LUMO of these sensitizers is above the TiO sub(2) conduction band. The sensitizer HYD4-OC8, has shown an overall conversion efficiency of 9.25%, whereas the standard sensitizer YD2-O-C8, has shown 9.40%.