Double Linker Triphenylamine Dyes for Dye-Sensitized Solar Cells

Abstract

Most organic dyes synthesized for dye-sensitized solar cells (DSC) use a single linker group to bind to the metal oxide photo-anode. Here we describe the synthesis and testing of two new triphenylamine dyes containing either two carboxylic acids 5-[2-(4-diphenylamino-phenyl)-vinyl]-isophthalic acid (10) or two cyanoacrylic acids (2Z, 2′Z)-3, 3′-(5-((E)-4-(diphenylamino) styryl)-1, 3-phenylene) bis (2-cyanoacrylic acid) (8) as linker groups. Full characterization data are reported for these dyes and their synthetic intermediates. DSC devices have been prepared from these new dyes either by passive or fast dyeing and the dyes have also been tested in co-sensitized DSC devices leading to a PCE (η = 5.4%) for the double cyanoacrylate linker dye (8) co-sensitized with D149. The dye:TiO2 surface interactions and dye excitations are interpreted using three modelling methods: density functional theory (at 0 K); molecular dynamics (at 298 K); time dependent density functional theory. The modelling results show the preferred orientation of both dyes on an anatase (1 0 1) TiO2 surface to be horizontal, and both the simulated and experimental absorption spectra of the dye molecules indicate a red shifted band for (8) compared to (10). This is in line with broader light harvesting and Jsc for (8) compared to (10).

Recent advances on visible light Thiophene-based photoinitiators of polymerization

“…Triphenylamine is a remarkable electron-donating group that was extensively used for the design of push-pull dyes. [291][292][293][294][295] Triphenylamine is also capable to drastically improve the solubility of dyes in solution by its tridimensional structure, impeding π-π stacking interactions. [296,297] Triphenylamine is also a candidate of choice for various chemical modifications.…”

Investigation of the Photon to Charge Conversion and Its Implication on Photovoltaic Cell Efficient Operation

“…The aforementioned concepts are enabled by some nano materials like graphene or carbon nanotubes (CNT) [71]. Broader light harvesting and increased current density have been successful due to the use of new sensitized dyes containing two carboxylic acids or two cyanoacrylic acids as linker groups to bind the metal oxide photo anode, instead of the conventional single linker group of the dye sensitized solar cell (DSSC) [72].…”

“…A promising expansion of the PV concept concerns graphene-based thermionic and thermo radiative converters. The thermionic efficiency may improve the efficiency by including various irreversibility losses, such as space-charge effects and non-radiative recombination or suppression [68], mainly due to graphene's excellent conductivity, mobility, and linear band gap structure [69][70][71][72]. Moreover, the thermo radiative cell is able to produce electric current from the coldness of the outer space due to the exploitation of the negative illumination effect [73][74][75][76][77][78][79][80].…”

Investigating the Molecular Orientation and Thermal Stability of Spiro‐OMeTAD and its Dopants by Near Edge X‐Ray Absorption Fine Structure

“…Recent work has also shown the importance of molecular orientation in light-harvesting dyes in dye-sensitized solar cells. [18,19] There are many variations of organic HTMs known, these can broadly be divided into families based on their core structure and include the "Spiro" HTMs [20] and planar HTMs such as triazatruxene [21] or triphenylamine (TPA). [22,23] The most popular of these organic HTMs being the Spiro-OMeTAD that has been the subject of intense research since the late 1990s.…”