Thieno[3,4-b]thiophene-Based Organic Dye for Dye-Sensitized Solar Cells

• Main Authors: ming-chih Tsai, 蔡明志
• Other Authors: Ching-Fa Yao
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/79515931487580343245

碩士 === 國立臺灣師範大學 === 化學系 === 99 === A novel series of metal-free organic dyes were synthesized via Stille coupling, Buchwald-Hartwig coupling and Knoevenagel condensation. These dyes are composed of an arylamine moiety as the electron donor, a conjugated spacer containing ethyl thieno[3,4-b]thiophene-2-carboxylate, and furan (or thiophene) as the electron transmitting bridge, and an 2-cyanoacrylic acid as the electron acceptor and anchoring group to the TiO2 surface. The lowbandgap thieno[3,4-b]thiophene entity was incorporated in the conjugated spacer of the sensitizer for red shifting the absorption band. Indeed, the charge-transfer absorption maximum of the sensitizer ranges from 477 to 553 nm. Cyclic voltammograms and absorption spectra were used to calculate the HOMO and LUMO energy levels of these dyes, The HOMO and LUMO energies fall in the range of 5.23−5.48 and 3.14−3.37 eV, respectively, which facilitate both electron injection to TiO2 and subsequent dye regeneration. Dye-sensitized solar cells (DSSCs) using these dyes exhibit high solar energy-to-electricity conversion efficiencies ranging from 1.23% to 5.31%, which reach 17−72% of the standard device of N719 fabricated and measured under the same conditions.