کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
176990 458961 2012 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
N-Aryl stilbazolium dyes as sensitizers for solar cells
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
N-Aryl stilbazolium dyes as sensitizers for solar cells
چکیده انگلیسی

Eight new N-arylstilbazolium chromophores with electron donating –NR2 (R = Me or Ph) substituents have been synthesized via Knoevenagel condensations and isolated as their PF6− salts. These compounds have been characterized by using various techniques including 1H NMR and IR spectroscopies and electrospray mass spectrometry. UV–vis absorption spectra recorded in acetonitrile are dominated by intense, low energy π → π* intramolecular charge-transfer (ICT) bands, and replacing Me with Ph increases the ICT energies. Cyclic voltammetric studies show irreversible reduction processes, together with oxidation waves that are irreversible for R = Me, but reversible for R = Ph. Single crystal X-ray structures have been determined for three of the methyl ester-substituted stilbazolium salts and for the Cl− salts of their picolinium precursors. Time-dependent density functional theory calculations afford reasonable predictions of ICT energies, but greater rigour is necessary for –NPh2 derivatives. The four new acid-functionalized dyes give moderate sensitization efficiencies (ca. 0.2%) when using TiO2-based photoanodes, with relatively higher values for R = Ph vs Me, while larger efficiencies (up to 0.8%) are achieved with ZnO substrates.

Figure optionsDownload as PowerPoint slideHighlights
► N-Arylstilbazolium dyes with –NR2 (R = Me/Ph) electron donor groups are studied.
► Replacing Me with Ph blue shifts the intramolecular charge-transfer (ICT) bands.
► Time-dependent density functional theory predicts the ICT energies reasonably well.
► Acid derivatives sensitize TiO2 with efficiencies of ca. 0.2%, but up to 0.8% on ZnO.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Dyes and Pigments - Volume 92, Issue 1, January 2012, Pages 766–777
نویسندگان
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