Triphenylamine/Tetracyanobutadiene-Based D-A-D pi-Conjugated Systems as Molecular Donors for Organic Solar Cells

Thlophene-based D-A-D pi-conjugated systems containing triphenylamine end groups connected to a 1,1,4,4-tetracyanobuta-1,3-diene acceptor by oligothiophene chains of variable length have been synthesized. These compounds show Interesting light-harvesting properties and low-lying HOMO levels. Preliminary results on bilayer heterojunction solar cells with C(60) as acceptor show power conversion efficiency higher than 1.0%

Structural modulation of internal charge transfer in small molecular donors for organic solar cells

Donor-acceptor molecules with small chain extension have been synthesized and used as active material in organic solar cells. The effect of fusion of a phenyl group on the end dicyanovinylene acceptor is discussed

Small D-pi-A Systems with o-Phenylene-Bridged Accepting Units as Active Materials for Organic Photovoltaics

Donor-acceptor (D--A) systems that combine triarylamine donor blocks and dicyanovinyl (DCV) acceptor groups have been synthesized. Starting from the triphenylamine (TPA)thiopheneDCV compound (1) as a reference system, various synthetic approaches have been developed for controlling the light-harvesting properties and energy levels of the frontier orbitals in this molecule. Thus, the introduction of methoxy groups onto TPA, the replacement of one phenyl ring of TPA by a thiophene ring, or the extension of the -conjugating spacer group lead to the modulation of the HOMO level. On the other hand, the fusion of the DCV group onto the vicinal thiophene ring by an ortho-phenylene bridge allows for a specific fine-tuning of the LUMO level. The electronic properties of the molecules were analyzed by using UV/Vis spectroscopy and cyclic voltammetry and the compounds were evaluated as donor materials in basic bilayer planar heterojunction solar cells by using C-60 as acceptor material. The relationships between the electronic properties of the donors and the performance of the corresponding photovoltaic devices are discussed. Bilayer planar heterojunction solar cells that used reference compound 1 and C-70 afforded power-conversion efficiencies of up to 3.7%

Catechol-appended TTF derivatives

EDT-TTF-CONHCatOH, a catechol-appended TTF derivative, 5 was synthesized through a straightforward strategy. The electronic absorption and the electrochemical investigations as well as molecular orbital calculations for compounds 4 and 5 have been performed. The electrochemical measurements of 5 indicate that it is a suitable candidate for the formation of zwitterionic molecular solids and also two-component radical cation salts. The crystal structure of compound 5 reveals supramolecular dimers assembled via a set of O-H center dot center dot center dot O hydrogen bonds between the catechol and amide units

Systèmes pi-conjugués D-A-D à cœur accepteur tétracyanobutadiène pour la conversion photovoltaïque

National audienc

Triphenylamine based D-A or D-A-D π-conjugated systems as molecular donors for organic solar cells

International audienc