Phenothiazine derivatives as organic sensitizers for highly efficient dye-sensitized solar cells

Abstract

A series of organic dyes containing a phenothiazine central unit were synthesized and were used effectively in the fabrication of dye-sensitized solar cells (DSSCs). A cyanoacrylate moiety was added at the C(3) position of the phenothiazine as an electron acceptor, and a triarylamine moiety was attached at the C(7) position as an electron donor. The DSSCs made with these dyes displayed remarkable quantum efficiency, ranging from 4.2-6.2% under an AM 1.5 solar condition (100 mW cm À2 ). A variety of substituents, i.e., methyl, hexyl and triphenylamino groups, were added at the N(10) of phenothiazine in order to optimize the incident photon-to-current conversion efficiency. Along the main chromophore a thiophenylene group was inserted at different positions to examine its influence on the properties of devices. The best performance was found in compound NSPt-C6, in which a hexyl group was attached at the N(10) of phenothiazine and a thiophenylene at the C(7) position. It displayed a short-circuit current (J sc ) of 14.42 mA cm À2 , an open-circuit voltage (V oc ) of 0.69 V, and a fill factor (ff) of 0.63, corresponding to an overall conversion efficiency of 6.22%. Their photophysical properties were analyzed with the aid of a time-dependent density functional theory (TDDFT) model with the B3LYP functional. Their photovoltaic behavior was further elucidated by the electrochemical impedance spectroscopy.

Spacer controlled photo-induced intramolecular electron transfer in a series of phenothiazine-boron dipyrromethene donor–acceptor dyads

“…All the reactions were carried out under nitrogen or argon atmosphere using dry and degassed solvents. -1, 3, 7, 9-tetramethyl-5-phenyldipyrrin (BODIPY), [51] 10-(n-hexyl)-10H-phenothiazine (1), [52] 10-(n-hexyl)-10H-phenothiazine-3-carbaldehyde (2) [53] were synthesized according to the literature procedures. The peak at m/z 212.29 corresponds to "10-methyl-10H-phenothiazine".…”

Molecular Engineering and Theoretical Investigation of Novel Metal-Free Organic Chromophores for Dye-Sensitized Solar Cells

“…These include, donor-p conjugation bridge-acceptor (D-p-A) [4], with auxiliary acceptors (D-p-A-p-A) [5], (D-A-p-A) [6], and auxiliary donors (D-p-D-p-A) [7], (D-D-A-p-A) [8] configurations. Among these, D-D-A-p-A strategy is receiving immense attention lately.…”

Synthesis and photovoltaic performance of asymmetric di-anchoring organic dyes

“…DP-3 and DP-4 have higher ε values than the well-known dye N719 (1.42 × 10 4 M -1 cm -1 ) [44], due to the extended conjugation, two donor units and two anchoring units. Generally, it is believed that a stronger absorption in a broader wavelength region is favorable for photocurrent generation in DSSCs because more photons can be efficiently harvested [45,46]. SP has a much lower value ε than DP-3 and DP-4, which indicates that it has a lower light harvesting capacity.…”