تحضير ودراسة نظرية لمشتقات صبغات الايميدازول الجديدة وتطبيقها في الخلايا الشمسية المحفزة بالصبغة

Rp- Synthesis and theoretical study of new imidazole derivatives dyes and their applicat.. pdf.

In this work, six free metal-organic dyes were designed and synthesized as the donor-π bridge-acceptor system in a one-pot condensation reaction and used as a sensitizer in DSSCs. The dyes that were recorded are imidazole derivatives, which are of two types. Type I are basically 2,4,5-trisubstituted imidazole derivatives (Scheme I) and the type II of dyes are 1,2,4,5-tetrasubstituted imidazole derivatives (Scheme II).
The first type is PP1 and the second type are containing five different substituents on (N-imidazole) ring such as (nitrobenzene (PP2), N,N-diethylpropan-1-amine (PP3), phenyl (PP4), chlorobenzene (PP5) and dichlorobenzene (PP6)) with investigation the effect of these substituents in the efficiency of the synthesized compounds as a DSSCs. Benzene and imidazole units were chosen as donor groups, for their electron-donating character and to avoid dye aggregation on the TiO2 surface. Basically, 2,4,5-trisubstituted imidazole units were used to comparative study of the performance of the sensitizers in the final devices. Benzene ring was chosen as the termination of the π-bridge. Carboxylic acid was chosen as both acceptor and anchor group on the TiO2 surface. All these dyes are characterized by FTIR, 1H-NMR, 13C-NMR, Mass spectra and supported by computational calculation. The dye PP3 with the alkyl chain substitution displayed the highest power conversion efficiency (PCE) of 2.01% (Jsc = 3.75 mA cm-2, Voc = 0.73 mV, FF = 73.9%) while the PP2 dye with the nitrobenzene substitution showed the lowest energy gap (Eg = 2.55 eV) and lowest PCE 0.96% (Jsc = 1.59 mA cm-2, Voc = 0.080 mV, FF = 61.6%).