The effects of second electron acceptor group on the performance of tetrazole-based nanocrystalline TiO2 sensitizers in DSSCs

Zahra Jafari Chermahini; Alireza Najafi Chermahini; Hossein A Dabbagh; Behzad Rezaei; Neda Irannejad

doi:10.1016/j.saa.2017.01.061

The effects of second electron acceptor group on the performance of tetrazole-based nanocrystalline TiO₂ sensitizers in DSSCs

Spectrochim Acta A Mol Biomol Spectrosc. 2017 May 5:178:79-85. doi: 10.1016/j.saa.2017.01.061. Epub 2017 Jan 30.

Authors

Zahra Jafari Chermahini¹, Alireza Najafi Chermahini², Hossein A Dabbagh¹, Behzad Rezaei¹, Neda Irannejad¹

Affiliations

¹ Department of Chemistry, Isfahan University of Technology, 84154-83111 Isfahan, Iran.
² Department of Chemistry, Isfahan University of Technology, 84154-83111 Isfahan, Iran. Electronic address: anajafi@cc.iut.ac.ir.

PMID: 28167362
DOI: 10.1016/j.saa.2017.01.061

Abstract

Three new organic sensitizers with two electron acceptor groups were synthesized and applied to nanocrystalline TiO₂ solar cells. The ethyl 2-(1H-tetrazol-5-yl) acetate, (2H-tetrazol-5-yl) acrylonitrile and 1H-tetrazole-5-acetic acid moieties were introduced to the triphenylamine as electron acceptor groups. The photophysical, electrochemical and photovoltaic properties of the solar cells based on the synthesized sensitizers were studied and compared with their counterparts of single electron acceptor type. Quantum chemical calculations were also carried out to consideration of the electronic and optical properties of these dyes. The dye with the (2H-tetrazol-5-yl) acrylonitrile electron acceptors showed the absorption maxima in the longer wavelength, compared to the dyes with ethyl 2-(1H-tetrazol-5-yl) acetate and 1H-tetrazole-5-acetic acid. The solar cell based on the dye with 1H-tetrazole-5-acetic acid showed the highest conversion efficiency of 3.53% (open circuit voltage=569mV, short circuit photocurrent density=11.50mAcm^-2, and fill factor of 54% under AM 1.5G conditions). The results also showed that the dyes with two electron acceptor groups gave the higher performance than the dyes with single electron acceptor.

Keywords: Anchoring group; Dye sensitized solar cell; Electron acceptor group; Sensitizer; Tetrazole.