Charge Carrier Mobility of Phenothiazine Functionalized TCBD Derivatives of Naphthalimide.

A set of naphthalimide functionalized push-pull chromophores NPI 1-3 were designed and synthesized via Pd-catalyzed Sonogashira cross-coupling followed by [2 + 2] cycloaddition-electrocyclic ring-opening reaction. The 1,8-naphthalimide (NPI) and 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) moiety acts as an acceptor unit, whereas phenothiazine (PTZ) unit acts as a donor unit. Their photophysical, electrochemical properties, and charge carrier mobilities were investigated.

Molecular Design and Alignment for Ambipolar SCLC Mobility in Self-Assembled Columnar Discogens.

The future of next-generation electronics relies on low-cost organic semiconductors that are tailored to simultaneously provide all requisite optoelectronic properties, focusing greatly on ambipolar charge-transport and solution processability. In this regard, room-temperature discotic liquid crystals (DLCs) are potential candidates, where quasi-1D self-assembly affords a charge-transport channel along their columnar axis. This work shows a molecular design strategy by utilizing anthraquinone as the primary motif, surrounded by ester functionalized tri-alkoxy phenyl units to develop room-temperature DLCs (1.

Solution Processable Se-annulated Swallow Tail Perylene Bisimide Exhibiting Room Temperature Columnar Phase and Efficient Ambipolar Charge Carrier Mobility.

This study presents a selenium-annulated perylene bisimide (PBI-Se) stabilizing room temperature columnar hexagonal phase with exceptionally low clearing temperature. The synthesis of this Se-annulated PBI (PBI-Se) was accomplished using the reductive Cadogan cyclization method, with the introduction of swallow tails to reduce the clearing temperature and improve solubility. In addition, the charge carrier mobility of the Se-bay annulated PBI is assessed by space charge limited current (SCLC) technique and juxtaposed with PBI as well as nitrogen and sulphur-bay-annulated PBIs.

Ambipolar macrocycle derived from spiro-xanthene and carbazole: synthesis, structure-property relationships, electronic properties and host-guest investigation.

For the first time, we present the detailed synthesis, photophysical, electrochemical, host-guest and charge transport properties of spiro[fluorene-9,9'-xanthene] (SFX) and carbazole macrocycle SPS-NR-02. The electron and hole transport values measured using the space charge limited current (SCLC) method resulted in ambipolar charge transport with an electron to hole mobility ratio of 0.39.

Syntheses and Properties of Hole-Transporting Biindenofluorenes.

Described herein is a straightforward approach to synthesizing three biindenofluorene (BIF) derivatives, composed of antiaromatic indenofluorene units, which are the first non-alternant congeners of known bipentacene. Dimerization of indeno[1,2-]fluorene and indeno[2,1-]fluorene units by connecting carbons 3 and 3' and carbons 2 and 2', respectively, is shown to influence the highest occupied and lowest unoccupied molecular orbital energy levels of the resulting BIFs, affording band gaps (1.5-1.

Highly Soluble Ambipolar anti-Perylene-3,4 : 9,10-bis(benzimidazole)s Stabilize a Room-Temperature Columnar Hexagonal Phase.

A new series of highly soluble perylene anti-bis(4,5-dialkoxybenzimidazole)s bearing branched flexible chains stabilizing room temperature columnar hexagonal phase and with balanced ambipolar charge carrier mobility is reported for the first time. Only the anti isomer was successfully separated and characterized. These compounds have a high extinction coefficient, small optical band gap and wide absorption range, thus making them a promising class of ambipolar organic semiconductors capable of self-organizing.

First example of ambipolar naphthalene diimide exhibiting a room temperature columnar phase.

A self-assembled ambipolar organic semiconductor based on naphthalene diimide with low clearing temperature, solution processability, and high molar extinction coefficient, exhibiting a room temperature columnar hexagonal liquid crystalline phase is reported.

Functionalized Benzothiadiazole Non-Fused A-D-A'-D-A Small Molecules for Effective Electron Mobilities and Metal-free Photocatalysis.

Three non-fused A-D-A'-D-A π-conjugated metal-free small molecules BT-IT1, BT-IBT2 and BT2F-IBT3 have been synthesized and their absorption characteristics and redox properties, as well as charge carrier mobilities have been investigated. The resultant molecules exhibited broad absorption in the range of 325-600 nm in solutions and in thin films the absorption range is 350-700 nm. These new conjugated small molecules showed low-lying HOMO energy levels (-5.

High hole mobility in room temperature discotic liquid crystalline tetrathienoanthracenes.

Tetrathienoanthracene (TTA), a new discotic core fragment, is explored that shows a remarkably high hole mobility (μh) of 4.22 cm2 V-1 s-1 at room temperature when used in space-charge limited current (SCLC) devices. Strong co-facial interactions (π-π, SS) among TTA cores along with a high tendency of the derivative to align homeotropically in the columnar mesophase over a large area in SCLC cells contributed to the top-class charge carrier mobility.

High Hole Mobility and Efficient Ambipolar Charge Transport in Heterocoronene-Based Ordered Columnar Discotics.

Heterocoronene, a new redox-active core fragment, is utilized for the synthesis of room-temperature columnar discotic liquid crystals (DLCs). Three wedge-shaped side chains having different lengths of alkyl tails are introduced at the periphery of the heterocoronene core to prepare three kinds of discotic molecules, (R = CH), (R = CH), and (R = CH). X-ray diffraction (XRD) analysis confirmed the packing variation in the columnar lattices regulated by alkyl chains of discrete length and steric bulk.

A New Approach to Compute the Porosity and Surface Roughness of Porous Coated Capillary-Assisted Low Pressure Evaporators.

The fundamental characteristics of metal coatings that influence heat transfer are porosity and surface roughness. It is a challenge to analyze the porosity and surface roughness due to the inadequate amount of copper per coated area. In this study, a new approach to non-invasively determine the porosity of metal films utilizing a helium pycnometer and computed micro-tomography (CMT) is presented.