Nonplanar Organic Sensitizers Featuring a Tetraphenylethene Structure and Double Electron-Withdrawing Anchoring Groups

Abstract

Two metal-free organic sensitizers containing two N,N-diethylaniline (DEA) moieties and a twisted 1,1,2,2-tetraphenylethene (TPE) structure, dye SD with one anchoring group and dye DD with two anchoring groups, were synthesized and applied in dye-sensitized solar cells (DSSCs). The introduction of a nonplanar TPE structure was used to form a series of propeller-like structures and reduce the tendency of dyes to randomly aggregate on TiO2 surface, but without importing an aggregation-induced emission (AIE) property. The thermal stabilities, UV-vis absorption spectra, electrochemical properties, and photovoltaic parameters of DSSCs with these two dyes were systematically studied and compared with each other. The overall conversion efficiencies (η) of 4.56% for dye SD and 6.08% for dye DD were obtained under AM 1.5 G irradiation.

Organic double D–π–A sensitizers based on 2,2′-(2,2 diphenylethene-1,1-diyl)dithiophene: π-conjugation fragment effect on the photovoltaic properties

“…[20][21][22] Recently, the light-emitting molecule tetraarylethylene 23 has attracted our interest, which can effectively promote the orderly aggregation of dyes without introducing aggregation-induced luminescence (AIE) characteristics. Since the Su group 24 first introduced the tetraphenylethylene (TPE) core into X-shaped dyes, more dyes have been introduced into this fragment at different sites. For example, Lin group 25 synthesized a series of di-anchoring TPEtethered YL dyes, providing a stronger ability to suppress charge recombination than the congener dyes.…”

Stimuli‐Responsive Properties of Aggregation‐Induced‐Emission Compounds Containing a 9,10‐Distyrylanthracene Moiety

“…Aggregation‐induced emission (AIE) is photophysical phenomenon associated with chromophore aggregation . AIE materials show enhanced emission from the aggregate or solid state in comparison with their dilute solutions, and AIE has been found in several systems, such as siloles, tetraphenylethylene (TPE), triphenylethylene, cyano distyrylbenzene, distyrylanthracene, and their derivatives . In the case of 9,10‐distyrylanthracene derivatives, the 9,10‐divinylanthracene segment can undergo an active rotation process in dilute solution that quenches the emission from luminophores.…”

“…[9] AIE materials showe nhanced emission from the aggregateo rsolid state in comparison with their dilute solutions, and AIE has been found in several systems, such as siloles, tetraphenylethylene (TPE), triphenylethylene, cyano distyrylbenzene,d istyrylanthracene, and their derivatives. [1,[10][11][12] In the case of 9,10-distyrylanthracene derivatives, the 9,10-divinylanthracene segment can undergo an active rotationp rocess in dilute solution that quenches the emissionf rom luminophores. However,i nt he aggregate state, the intramolecular rotation, that is the nonradiative decay channel, is blocked, and this leads to the enhanced emission of molecules.…”

A Facile Approach towards Fluorescent Nanogels with AIE-Active Spacers

“…Since being developed by Tang’s group in 2001 [36], AIE strategy has opened a new horizon to luminescent and photoelectric materials design, witnessed by the successful synthesis of various novel AIEgens and their derivatives [37,38,39,40]. The emissions of current AIEgens have covered a wide spectrum range from blue to red or even to infrared, with higher photo and chemical stability, brightness, and longer lifetime, and found applications in bio-imaging [41,42,43,44,45,46,47], cancer theranostics [48,49], sensors [50,51,52,53], organic light emission diodes (OLED) [54,55,56,57], and other photovoltaic devices [58,59,60]. Benefiting from its intrinsic emissive characteristics, the AIEgen unit is an ideal fluorophore and crosslinker for constructing fluorescent organic nanogels in which the AIEgen moiety is fixed in a limited space, leading to high local concentration with highly restricted intramolecular movability, due to the huge steric hindrance of the polymeric network.…”