Synthesis and characterization of novel thieno[3,2-b]thiophene based metal-free organic dyes with different heteroaromatic donor moieties as sensitizers for dye-sensitized solar cells

• Autor(a) principal: Fernandes, Sara Sofia Marques
• Data de Publicação: 2017
• Outros Autores: Castro, Maria Cidália Rodrigues, Mesquita, I., Andrade, L., Mendes, A., Raposo, M. Manuela M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/44490
• topic: Dye sensitized solar cells (DSSCs); Heterocyclic organic dye; Metal-free thieno[3,2-b]thiophene dye; Cyanoacetic acid anchoring group; Heterocyclic donor groups; Co-adsorption; Synthesis; UV-Vis.; Fluorescence; Push-pull systems; Dye sensitized solar cells; Metal-free thieno[3,2-b]thlophene dye; Ciências Naturais::Outras Ciências Naturais; Science & Technology

Four novel heterocycle dyes 3a-d were synthesized in order to study the variations produced in the optical, electronic and photovoltaic properties by substitution of different electron-rich heterocyclic groups to the thieno[3,2-b]thiophene system. The final push-pull conjugated dyes 3a-d were synthesized by Suzuki-Miyaura coupling reaction followed by Knoevenagel condensation of the corresponding aldehyde precursors with cyanoacrylic acid 2a-d. These new push-pull systems are based on a thieno[3,2-b]thiophene spacer, a cyanoacetic acid anchoring group and several electron-rich heterocycles (thiophene, pyrrole and furan) as donor groups. The multidisciplinary study concerning the optical, redox and photovoltaic characterization of the dyes reveals that compound 3b bearing a hexyl-bithiophene donor group/heterocyclic spacer exhibits the best overall conversion efficiency (2.49%) as sensitizer in nanocrystalline TiO2 dye sensitized solar cells. Co-adsorption studies between N719 and 3b revealed that upon addition of N719 co-adsorbent, the optimized cell efficiencies were improved by 16–77%. The best efficiency was 4.40%, corresponding to 54% of the photovoltaic performance of the N719-based DSSC fabricated and measured under similar conditions.