Carbazole-based sensitizers for potential application to dye sensitized solar cells

Journal of Chemical Sciences

Naresh Duvva¹  Lingamallu Giribabu1¹  Ravi Kumar Kanaparthi¹  Jaipal Kandhadi¹  Paolo Salvatori2²  Filippo De Angelis2²  Gabriele Marotta² 

[1] Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India$$;Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze Tecnologie Molecolari, Via Elce di Sotto 8, I-06123, Perugia, Italy$$

关键词: Sensitizer;    metal-free;    push-pull;    carbazole;    DFT.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Two push-pull molecules employing carbazole and alkyl thiophene (CAR-THIOHX) or carbazole and triphenylamine (CAR-TPA) as donor moieties, with the cyanoacrylic group as the acceptor, have been designed and synthesized by simple organic transformations. Photophysical and electrochemical studies revealed the potential of these two systems in dye sensitized solar cells (DSSC). Under standard irradiation conditions, CAR-TPA and CAR-THIOHX exhibited 2.12 and 1.83% of overall power conversion efficiencies respectively. The moderate photovoltaic efficiency of the sensitizers has been attributed to the poor light absorption of the sensitizers in the visible region. Density functional theory (DFT) calculations have shown a strong intramolecular charge transfer character, with the HOMOs of both the sensitizers exclusively localized on the corresponding donor moieties and LUMOs on the cyanoacrylic acid acceptor. On the other hand, the calculated high dihedral angle between the carbazole donor and the phenyl bridge for these sensitizers impedes the conjugation along the dyes backbone, and thus leads to less extended and intense absorption spectra in the visible region.

【 授权许可】

Unknown