Synthesis and characterization of stable main-chain polymeric metal complex dyes based on phenothiazine or carbazole units for dye-sensitized solar cells

Abstract

Four novel polymeric metal complex dyes (P1-P4) based on phenothiazine or carbazole derivatives, containing complexes of diaminomaleonitrile with Zn(II) or Co(II) were synthesized and characterized by gel permeation chromatography, Fourier transform infrared spectroscopy, UV-visible absorption, cyclic voltammetry and elemental analysis. The dyes based on carbazole derivatives (P3, P4) exhibited wider absorption spectra, and after replacement of the Co(II) coordinated ion with Zn(II), a bathochromic shift in the absorption spectrum was observed. When used in dye-sensitized solar cells (DSSCs), the device sensitized by P3 exhibited the best photocurrent conversion efficiency (2.06%) under standard illumination with a short-circuit photocurrent density (J sc ) of 4.54 mA cm − 2 , an open-circuit photovoltage (V oc ) of 0.67 V and a fill factor (ff) of 67.8%. Moreover, these dyes all exhibited excellent chemical and thermal stability. These results reveal a new path for the design of novel conjugated organic polymer dyes for highly efficient DSSCs.

Solvent effects on the intramolecular charge transfer excited state of 3CzClIPN: a broadband transient absorption study

“…[1][2][3] In this regard, ICT model organic molecules with specific photophysical properties have drawn much attention of the scientific community, with their utilization as dye-sensitizers in solar cells (DSSCs), photocatalysts (PCs), and nonlinear optical (NLO) materials, conferring high efficiency and excellent yields. [4][5][6][7][8][9] Organic ICT-based molecules consist of donor (D)-acceptor (A) pairs, which can be linked through p-conjugated electron bridges (D-p-A) that promote the electron delocalization over the molecule and facilitate donor-acceptor interactions. [10][11][12] Recently, carbazole derivatives have been extensively studied with the carbazole core (Cz) serving as an excellent ICT donor.…”