The development of new organic semiconductors with improved performance in thin film transistors (OTFTs) is a major challenge for materials chemists. There particular need to develop air-stable n-channel (electron-conducting) comparable that p-channel (hole-conducting) materials, electronics realize the benefits complementary circuit design, i.e., ability switch either positive or negative gate voltages. have been significant advancements past five years. In terms standard OTFT metrics such...

Organic semiconductors based on pi-conjugated oligomers and polymers constitute the active elements in new generations of plastic (opto)electronic devices. The performance these devices depends largely efficiency charge-transport processes; at microscopic level, one major parameters governing transport properties is amplitude electronic transfer integrals between adjacent oligomer or polymer chains. Here, quantum-chemical calculations are performed model systems to address way chains...

Theoretical investigations of charge transport in organic materials are generally based on the "energy splitting dimer" method and routinely assume that parameters (site energies transfer integrals) determined from monomer dimer calculations can be reliably used to describe extended systems. Here, we demonstrate this transferability fail even molecular crystals with weak van der Waals intermolecular interactions, due substantial (but often ignored) impact polarization effects, particularly...

We describe at the quantum-chemical level main parameters that control charge transport molecular scale in discotic liquid crystals. The focus is on stacks made of triphenylene, hexaazatriphenylene, hexaazatrinaphthylene, and hexabenzocoronene molecules derivatives thereof. It found a subtle interplay between chemical structure their relative positions within determines properties; features required to promote high mobilities materials are established basis calculated structure−property...

Rubrene has recently attracted much attention in the field of organic semiconductors because its very high mobilities at room temperature. These observations are a priori surprising, since tetraphenyl substitution tetracene backbone (see Figure) is expected to lead weak intermolecular interactions and, as result, low carrier mobilities. This theoretical work provides clear explanation for origin

The reorganization energy in pentacene is reported on the basis of a joint experimental and theoretical study ionization using high-resolution gas-phase photoelectron spectroscopy, semiempirical intermediate neglect differential overlap calculations, first-principles correlated quantum-mechanical calculations at MP2 density functional theory levels. upon positive determined both experimentally theoretically to be remarkably low. This one key element that allows rationalize extremely high...

We report structural and electrical transport properties of a family π-stacking soluble organic semiconductors, N,N'-dialkyl-3,4,9,10-perylene tetracarboxylic diimides (alkyl − pentyl [1], octyl [2], dodecyl [3]). The structures evaporated polycrystalline films 1−3 were studied using X-ray diffraction atomic force microscopy. Films pack similarly with the direction π−π overlap in substrate plane. Organic thin film transistors (OTFTs) based on deposited SiO2 gate dielectric showed linear...

The hole-vibrational coupling is reported for anthracene, tetracene, and pentacene on the basis of a joint experimental theoretical study ionization spectra using high-resolution gas-phase photoelectron spectroscopy first-principles correlated quantum-mechanical calculations. found to be significantly smaller than electron-vibrational in case these oligomers; however, both quantities are predicted converge same value when increasing chain length.

Quantum-chemical calculations coupled with a tight binding band model are used to study the charge carrier mobilities in oligoacene crystals. The transfer integrals for all nonzero interactions four crystalline oligoacenes (naphthalene, anthracene, tetracene, and pentacene) were calculated, then construct excess electron hole structures of crystals approximation. From these structures, thermal-averaged velocity–velocity tensors constant-free-time constant-free-path approximations materials...

Perylene tetracarboxylic diimide (PTCDI) derivatives stand out as one of the most investigated families air-stable n-type organic semiconductors for thin-film transistors. Here, we use density functional theory to illustrate how it is possible control charge-transport parameters PTCDIs a function type, number, and positions substituents. Specifically, two strategies functionalization related core end substitutions are investigated. While end-substituted present same molecular backbone, their...

The charge-transport parameters of the perfluoropentacene and perfluorotetracene crystals are studied with a joint experimental theoretical approach that combines gas-phase ultraviolet photoelectron spectroscopy density functional theory. To gain better understanding role perfluorination, results for compared to those their parent oligoacenes, is, pentacene tetracene. Perfluorination is calculated increase ionization potentials electron affinities by approximately 1 eV, which expected reduce...

We present a multimode vibrational analysis of the gas-phase ultraviolet photoelectron spectra first ionization in anthracene, tetracene, and pentacene, using electron-vibration constants computed at density functional theory level. The each molecule exhibits high-frequency vibronic structure; it is shown that this regularly spaced feature actually consequence collective action several modes rather than result interaction with single mode. interpret terms missing mode effect. also discuss...

Petacene is one of the most promising organic semiconductors for thin-film transistors. Transport measurements in past have established presence shallow traps but their origins remained a mystery. Here we show that vapor-deposited crystalline pentacene thin films are due to local defects resulting from sliding molecules along long molecular axis, while two-dimensional packing maintained. Electronic structural calculation confirms these shallow-charge with energies ⩽100meV above (below)...

The vibrational coupling in the ground and excited states of positively charged naphthalene, anthracene, tetracene, pentacene molecules is studied on basis a joint experimental theoretical study ionization spectra using high-resolution gas-phase photoelectron spectroscopy first-principles correlated quantum-mechanical calculations. Our results reveal that, while main contribution to relaxation energy state oligoacene systems comes from high-energy vibrations, excited-state energies show...

A series of new quinodimethane-substituted terthiophene and quaterthiophene oligomers has been investigated for comparison with a previously studied quinoid oligothiophene that demonstrated high mobilities ambipolar transport behavior in thin-film transistor devices. Each quinoidal thiophene derivative shows reversible one-electron oxidation between 0.85 1.32 V, quasi-reversible second 1.37 1.96 two-electron reduction −0.05 −0.23 V. The solution UV−vis−NIR spectrum each compound is dominated...

Abstract A theoretical study using density functional theory is undertaken to gain insight into how the structural, electronic, and electron‐transfer characteristics of three Fluoroarene‐oligothiophene semiconductors influence preferred transport electrons versus holes in field‐effect transistor applications. The intermolecular electronic coupling interactions are analyzed through both a simplified energy‐splitting dimer (ESID) model as function entire Hamiltonian order understand impact...

We have performed classical molecular dynamics simulations and quantum-chemical calculations on crystals of anthracene perfluoropentacene. Our goal is to characterize the amplitudes room-temperature displacements corresponding thermal fluctuations in electronic transfer integrals, which constitute a key parameter for charge transport organic semiconductors. show that lead Gaussian-like distributions integrals centered around values obtained equilibrium crystal geometry. The calculated been...

We calculated the nonlinear optical properties of 24 azo-enaminone derivatives, incorporating solvent effects on their geometric and electronic structure, to assess impact environment these properties. Namely, we incorporated chloroform, tetrahydrofuran, acetone, ethanol, methanol, dimethyl sulfoxide in our calculations compared results with gas-phase calculations. To account for electron correlation NLO properties, performed at MP2/6-31G(p)//MP2/6-31G(d) level set. The polarizable continuum...

The performance of sensing and optical devices is closely linked to the molecular polarizability response, a property significantly influenced by tensor's isotropic anisotropic components. In this study, we investigate impact vibrational motion on polarizability. We analyze how intramolecular vibrations affect polar properties molecules commonly employed in refrigerants gas detection technologies. Our computational estimates align well with experimental data. It revealed that effects can...

Density functional theory calculations together with highly resolved gas-phase ultraviolet photoelectron spectroscopy have been applied to oligothiophene chains up eight thiophene rings. One of the important parameters governing charge transport properties in condensed phase is amount energy relaxation upon ionization. Here, we investigate impact on this parameter backbone flexibility present oligothiophenes as a result inter-ring torsional motions. With respect oligoacenes that are...

Organic solar cells based on the combination of squaraine dyes (as electron donors) and fullerenes acceptors) have recently garnered much attention. Here, molecular dynamics simulations are carried out to investigate evolution a squaraine–C 60 bilayer interface as function orientation order underlying layer. Electronic couplings between main electronic states involved in exciton dissociation charge (polaron pair) recombination derived for donor–acceptor complexes extracted from simulations....

Two new benzothiadiazole-triazole-linked lapachone derivatives were designed, synthesized and characterized by 1D 2D NMR spectroscopy. Their photophysical properties also investigated. Theoretical calculations (DFT), based on the molecular design of compounds, allowed a better understanding derivatives' stability behaviour, especially in excited state. This manuscript describes discussion architecture which is two substitutions at positions 4- 7- important 2,1,3-benzothiadiazole (BTD) core....

We report the structural and electrical characterization of thin films organic semiconductor molecules consisting an oligothiophene core capped with electron-withdrawing tricyanovinyl (TCV) groups. X-ray diffraction atomic force microscopy evaporated three different TCV-capped oligothiophenes showed that were highly crystalline. Electrical transport was measured in film transistors employing silver source drain contacts channel probes to correct for contact resistance. Three compounds...

In this work we use gap-fitting procedure to tune the long-range corrected functionals and accurately investigate electronic optical properties of five main molecules composing Buriti oil (extracted from Mauritia flexuosa L.) in framework density functional theory (DFT) time-dependent (TD) DFT. The characteristic length (1/ω) was observed be entirely system dependent, though concluded that its determination is fundamental importance rescue geometrical, electronic, with accuracy. We...