Nanoparticles of Push-Pull Triphenylamine-Based Molecules for Light-Controlled Stimulation of Neuronal Activity.

Organic semiconductor materials with a unique set of properties are very attractive for interfacing biological objects and can be used for noninvasive therapy or detection of biological signals. Here, we describe the synthesis and investigation of a novel series of organic push-pull conjugated molecules with the star-shaped architecture, consisting of triphenylamine as a branching electron donor core linked through the thiophene π-spacer to electron-withdrawing alkyl-dicyanovinyl groups. The molecules could form stable aqueous dispersions of nanoparticles (NPs) without the addition of any surfactants or amphiphilic polymer matrixes with the average size distribution varying from 40 to 120 nm and absorption spectra very similar to those of human eye retina pigments such as rods and green cones.

Spectrally Selective Full-Color Single-Component Organic Photodetectors Based on Donor-Acceptor Conjugated Molecules.

Photodetectors based on organic materials are attractive due to their tunable spectral response and biocompatibility, meaning that they are a promising platform for an artificial human eye. To mimic the photoelectric response of the human eye, narrowband spectrally-selective organic photodetectors are in great demand, and single-component organic photodetectors based on donor-acceptor conjugated molecules are a noteworthy candidate. In this work, we present single-component selective full-color organic photodetectors based on donor-acceptor conjugated molecules synthetized to mimic the spectral response of the cones and rods of a human eye.

Luminescence of Agrotextiles Based on Red-Light-Emitting Organic Luminophore and Polypropylene Spunbond Enhances the Growth and Photosynthesis of Vegetable Plants.

The impact of a light-transforming covering on photosynthetic activity and growth processes in lettuce and white cabbage plants grown in a glass greenhouse was studied. Plants were covered with agrotextile, a polypropylene (PP) nonwoven spunbond coated with polylactide varnish containing a new organic luminophore (LUM), which absorbs sunlight mainly in the 460-560 nm region and efficiently reradiates it in the red spectral region with a maximum at 660 nm. For comparison, simultaneously two references agrotextiles without LUM or containing a non-luminescent chromophore (ABS) with an absorption spectrum close to that of LUM were as well investigated.

In Situ Coupling Applied Voltage and Synchrotron Radiation: Operando Characterization of Transistors.

A compact voltage application setup has been developed for in situ electrical testing of organic field effect transistors in combination with X-ray scattering studies at a synchrotron beamlines. Challenges faced during real condition in-operando test of newly developed OFETs originated an idea of creation of a new setup which excludes number of factors that make experiments complicated. The application of the setup is demonstrated on a prototype of an organic transistors based on α,ω-dihexyl-α-quaterthiophene molecules.

Excited state dynamics and exciton diffusion in triphenylamine/dicyanovinyl push-pull small molecule for organic optoelectronics.

Triphenylamine-based small push-pull molecules have recently attracted substantial research attention due to their unique optoelectronic properties. Here, we investigate the excited state de-excitation dynamics and exciton diffusion in TPA-T-DCV-Ph-F small molecule, having simple chemical structure with asymmetrical architecture and end-capped with electron-withdrawing p-fluorodicyanovinyl group. The excited state lifetime in diluted solutions (0.

Phase Transitions and Formation of a Monolayer-Type Structure in Thin Oligothiophene Films: Exploration with a Combined In Situ X-ray Diffraction and Electrical Measurements.

A combination of in situ electrical and grazing-incidence X-ray diffraction (GIXD) is a powerful tool for studies of correlations between the microstructure and charge transport in thin organic films. The information provided by such experimental approach can help optimizing the performance of the films as active layers of organic electronic devices. In this work, such combination of techniques was used to investigate the phase transitions in vacuum-deposited thin films of a common organic semiconductor dihexyl-quarterthiophene (DH4T).

Large-Size Single-Crystal Oligothiophene-Based Monolayers for Field-Effect Transistors.

High structural quality of crystalline organic semiconductors is the basis of their superior electrical performance. Recent progress in quasi two-dimensional (2D) organic semiconductor films challenges bulk single crystals because both demonstrate competing charge-carrier mobilities. As the thinnest molecular semiconductors, monolayers offer numerous advantages such as unmatched flexibility and light transparency as well  they are an excellent platform for sensing.

Triphenylamine-Based Push-Pull Molecule for Photovoltaic Applications: From Synthesis to Ultrafast Device Photophysics.

Small push-pull molecules attract much attention as prospective donor materials for organic solar cells (OSCs). By chemical engineering, it is possible to combine a number of attractive properties such as broad absorption, efficient charge separation, and vacuum and solution processabilities in a single molecule. Here we report the synthesis and early time photophysics of such a molecule, TPA-2T-DCV-Me, based on the triphenylamine (TPA) donor core and dicyanovinyl (DCV) acceptor end group connected by a thiophene bridge.

Highly Luminescent Solution-Grown Thiophene-Phenylene Co-Oligomer Single Crystals.

Thiophene-phenylene co-oligomers (TPCOs) are among the most promising materials for organic light emitting devices. Here we report on record high among TPCO single crystals photoluminescence quantum yield reaching 60%. The solution-grown crystals are stronger luminescent than the vapor-grown ones, in contrast to a common believe that the vapor-processed organic electronic materials show the highest performance.

Nanostructured organosilicon luminophores and their application in highly efficient plastic scintillators.

Organic luminophores are widely used in various optoelectronic devices, which serve for photonics, nuclear and particle physics, quantum electronics, medical diagnostics and many other fields of science and technology. Improving their spectral-luminescent characteristics for particular technical requirements of the devices is a challenging task. Here we show a new concept to universal solution of this problem by creation of nanostructured organosilicon luminophores (NOLs), which are a particular type of dendritic molecular antennas.

Structure and properties of functionalized bithiophenesilane monodendrons.

This study reports a focal group modification of bithiophenesilane monodendrons and its effect on their molecular ordering in solution, bulk, and surface. We investigated hydrophobic MDn monodendrons and COOH-functionalized MDn-COOH monodendrons with generations, n=0, 1, 2, and 3. We observed that increasing the number of branches led to the progressive blue shift, indicating distorted packing of branched thiophene fragments of MDn.

Facile synthesis and optical properties of bithiophenesilane monodendrons and dendrimers.

Three generations of bithiophenesilane monodendrons and dendrimers consisting of 3-45 2,2'-bithiene-5,5'-diyl units were synthesized by means of effective coupling reactions between the corresponding bithienyllithium derivatives and chlorosilanes. These compounds show efficient photoluminescence in the violet-blue region, the quantum yield of which is 5-15 times higher than that for the parent bithiophene or bithiophenesilanes.