Acid azo dyes for efficient molecular photovoltaic: study of dye-sensitized solar cells performance

In this paper we sensitized three free-metal azo days Dye 1, Dye 2 and Dye 3 based on 1,8-naphthalimide with n-propyl as the electron donor group. We used sulfonic acid and hydroxyl substituents as the electron acceptor anchoring group in synthesized dyes. The proposed dyes were sensitized from acenaphthene as the starting material by standard reactions and characterized by different techniques such as melting point, FTIR, 1HNMR, elemental analysis and UV-Visible spectroscopy after purification. Spectrophotometric measurements of the azo dyes in solution and on a TiO2 substrate were carried out in order to assess changes in the status of the dyes. The wavelength of maximum absorption for Dye 1, Dye 2 and Dye 3 in solution are 530 nm, 568 nm and 550 nm and on TiO2 films are 552 nm, 591 nm and 575 nm, respectively. Finally, the proposed dyes used as sensitizer in a dye solar cell structure and their photovoltaic properties investigated. The Conversion efficiency for Dye 1, Dye 2 and Dye 3 are 2.11 and 2.32 and 2.17, respectively.