S7ynthesis and investigation of double alternating azo group in novel para-azo dyes containing nitro anchoring group for solar cell application

To study the effect of Thiazole (as a heterocycle with donation group) in DSSCs, sample A was made without heterocycle, samples B and C contain one Thiazole and various donor group but sample D had two Thiazole group. Moreover, the effects of a double Azo group, and increasing the length of pi-conjugation by reducing band gap trough heterocycle rings (donor-donor-pi-acceptor system) and Nitro anchoring group were investigated. Nitro groups disappeared in IR at about 1340 and 1598 cm(-1) which indicates that dyes successfully connected on TiO2. UV-vis and DRS analysis was studied in visible region that showed Red-shifts for the samples. The HOMO values obtained from the CV tests were calculated between -5.03 and 5.13 eV. The results show that D sample was better than others, showing a 0.5 V increase in its open-circuit voltage in the IV analysis. From the Electrochemical impedance spectroscopy (EIS), R-ct value for D cell was measured to be 73.35 K Omega, which is bigger than the other samples, and in line with I-V analysis results. (C) 2019 Elsevier B.V. All rights reserved.