Details

Autor(en) / Beteiligte

• Li, Sie-Rong
• Lee, Chuan-Pei
• Yang, Po-Fan
• Liao, Chia-Wei
• Lee, Mandy M.
• Su, Wei-Lin
• Li, Chun-Ting
• Lin, Hao-Wu
• Ho, Kuo-Chuan
• Sun, Shih-Sheng

Titel

Structure-Performance Correlations of Organic Dyes with an Electron-Deficient Diphenylquinoxaline Moiety for Dye-Sensitized Solar Cells

Ist Teil von

• Chemistry : a European journal, 2014-08, Vol.20 (32), p.10052-10064

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2014

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• The high performances of dye‐sensitized solar cells (DSSCs) based on seven new dyes are disclosed. Herein, the synthesis and electrochemical and photophysical properties of a series of intentionally designed dipolar organic dyes and their application in DSSCs are reported. The molecular structures of the seven organic dyes are composed of a triphenylamine group as an electron donor, a cyanoacrylic acid as an electron acceptor, and an electron‐deficient diphenylquinoxaline moiety integrated in the π‐conjugated spacer between the electron donor and acceptor moieties. The DSSCs based on the dye DJ104 gave the best overall cell performance of 8.06 %; the efficiency of the DSSC based on the standard N719 dye under the same experimental conditions was 8.82 %. The spectral coverage of incident photon‐to‐electron conversion efficiencies extends to the onset at the near‐infrared region due to strong internal charge‐transfer transition as well as the effect of electron‐deficient diphenylquinoxaline to lower the energy gap in these organic dyes. A combined tetraphenyl segment as a hydrophobic barrier in these organic dyes effectively slows down the charge recombination from TiO2 to the electrolyte and boosts the photovoltage, comparable to their RuII counterparts. Detailed spectroscopic studies have revealed the dye structure–cell performance correlations, to allow future design of efficient light‐harvesting organic dyes. Solar system: Dye‐sensitized solar cells based on dipolar organic dyes with a diphenylquinoxaline moiety exhibit a broad absorption profile of incident photon‐to‐electron conversion efficiency (IPCE) approaching the near‐infrared region (see figure). After tuning the π‐conjugated spacer, the solar cell based on dye DJ104 provides a remarkably high IPCE performance and also a high efficiency of 8.06 %.