Dye-Sensitized Solar Cells - DSSC: Structure-Property Relationship of Co-adsorbent

• DOI: https://doi.org/10.22533/at.ed.317582501106

• Palavras-chave: Dye-Sensitized Solar Cells; Co-adsorbent; Tetrazole

• Keywords: Dye-Sensitized Solar Cells; Co-adsorbent; Tetrazole

• Abstract: Two new compounds based on the phenyltetrazole system, 5-(4-octiloxyphenyl)tetrazole (LTz-3) and N,N-diethyl-4-{[(4’-nitro-2’-tetrazoyl)phenyl]diazenyl}aniline (SD-3), were synthesized and characterized as co-adsorbents in Dye-Sensitized Solar Cells (DSSCs). The effects of hydrophobic chain length and anchoring group on the properties of DSSCs containing the previously reported dye HD-14 and compared with the benchmark deoxycholic acid (DCA) are described. The charge-transfer resistance of dye/TiO2 interface followed the order HD-14 – SD-3  > HD-14 – LTz-3 > HD-14 –DCA. However, the VOC for the dye HD-14 with co-adsorbent DCA was 0.70 V, for the and the dye HD-14 with co-adsorbent LTz-3 was 0,70 V and for the dye HD-14 with co-adsorbent SD-3 was 0,67 V. Co-adsorbents LTz-3 and SD-3 achieved mean solar-to-power conversion efficiencies (%η), for three devices, of 9.22 and 7.50, respectively, compared to 8.90 for DCA under the same experimental device conditions. For LTz-3 co-adsorbent, the results can be attributed to the repellent effect of the long alkyl chain. For SD-3, it is possible that the volume of the co-adsorbent chain makes it difficult to form a more compact layer between the dye and the co-adsorbent. This allows the electrolyte to approaches, reducing the electron-injection efficiency into TiO2.