چكيده به لاتين
One of the most important and determinative challenge of designing dye sensitized slar cells (DSSCs) is developing dyes with optimized molecular structure and apt optical properties and electrochemical and electronic features. In this sudy, four novel organic triphenylamine-based dyes with D-π-A framework and various π-bridges which consist of benzene (B), naphthalene (N), anthracene (A) and ferrocene (Fc) units were synthesized and applied for as sensitizer of dye-sensitized solar cells (DSSCs). These dyes were compared for considering impact of π-bridges on power conversion efficiency (η) of relative DSSCs b characterizing optical, electrochemical, interfacial and photovoltaic (PV) aspects. For the mentioned results some key analysis were applied that consist of Fourier transform-infrared (FT-IR) spectroscopy, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), field-emission scanning electron microscopy (FESEM) and linear sweep voltammetry (LSV), They evaluated The results indicated that the number of aromatic rings in π-bridge unit of triphenylamine-based dyes surprisingly could be able to adjust not only the optical features, but also the electrochemical parameters that could be tuned to the optimum values. The maximum absorption wavelength (λmax) of these dyes were obtained 512, 524, 541 and 532 nm that provided the high molar absorption coefficient (ε) about ⁓17,000, ⁓ 20,000, ⁓ 22,000 and ⁓21,000 M-1 cm-1 for these dyes, respectively. The η of DSSCs could be ordered as ηTPA-Fc (5.42%) > ηTPA-A (5.01%) > ηTPA-N (4.60%) > ηTPA-B (4.46%), while the short-circuit current density (JSC), open-circuit voltage (VOC) and file factor (FF) of these DSSCs were obtained as JSC,TPA-Fc (14.60 mA cm-2 ) > JSC,TPA-A (14.21 mA cm-2 ) > JSC,TPA-N (13.88 mA cm-2 ) > JSC,TPA-B (12.91 mA cm-2 ) and VOC,TPA-Fc (652.26 mV) > VOC,TPA-A (629.52 mV) > VOC,TPA-N (624.83 mV) > VOC,TPA-B (619.15 mV) and FFTPA- Fc (57 %) > FFTPA-A (56 %) > FFTPA-B (55 %) > FFTPA-N (53 %), respectively, under the air mass (AM) 1.5 G standard light condition. The impact of the mentioned π-bridges on electronic structure of dyes and the intramolecular charge transfer (ICT) were considered by measuring highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) levels and band gap (Eg) using density functional theory (DFT) quantum calculation method. For the mentioned results some key analysis was applied that consist of Fourier transform-infrared (FT-IR) spectroscopy, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), field-emission scanning electron microscopy (FESEM) and linear sweep voltammetry (LSV) that inferred to the fact that that synthesizing organic dyes with a long conjugated π-bridges could provide well-matched HOMO and LUMO levels, higher ε and stronger “push-pull” effect in molecular building block that can enhance the η values. As another key finding of this study it could be referred to the fact that effect of the incorporating Fc π-bridge which empowers the ICT from donor (D) to acceptor (A) due to presence of quantum interference effects (QIEs). This result discloses a new trend for designing more efficient organic dye to find application in DSSCs.
