Abstract :

New dye sensitizers based on an oligothiophene cyanoacrylic acid derivativewere synthesized and characterized for solar cell applications. The structuresof the new dyes prepared as sensitizers based on oligothiophenes,namely5,5''-di-2-cyanoacrylic acid [2,2':5',2''-terthiophene] (dye1),[2,2':5',2''-terthiophene]-5-cyanoacrylic acid(dye2), and [2,2':5',2'':5'',2'''-quaterthiophene]-5-cyanoacrylic acid(dye3) were confirmed by elementalanalysis, mass spectrometry, and 1H-NMR spectral data. The P3HT/dye2/nc-TiO2 solar cell produced the highest efficiency of 0.05% with an open circuitvoltage of 0.65V compared to dyes 1 and 3 solar cells. That may have beenattributed to the dyes’ molecular structure, which had different chain lengthsand numbers of groups of cyanoacrylic connected to the dyes’ thiophenemoiety The dark current suppressed in the P3HT/dye2/nc-TiO2 solar cellsindicated the formation of the charge blocking layer, which produced anenhanced open-circuit voltage accompanied by a high onset voltage.