The precise control of molecular packing patterns in solid-state materials is crucial for determining their charge transport properties. This study systematically investigates the molecular packing patterns and charge transport properties of triisopropylsilylacetylene (TIPS)-benzobenzene molecules functionalized with different molecular lengths using benzocyclobutadiene (BCBD) as a linker to connect polycyclic aromatic hydrocarbons. In the solid state, these molecules exhibited both herringbone stacking and 1D/2D π-stacking. We discovered an intrinsic relationship between the stacking motifs and the position of the TIPS in the investigated systems. Depending on the ratio (R) of skeleton lengths at both ends of the main chain with TIPS as the split point in the different ranges of ∼2.0, 2.0∼3.0, and 3.0∼, these crystals exhibited different packing patterns. Meanwhile, the R value is closely related to the anisotropy of mobility of these organic semiconductors. Multi-scale calculations, including density functional theory (DFT) and molecular dynamics (MD) simulations, were employed to examine the impact of incorporating the BCBD structural moiety on charge transport properties. The results demonstrate that BCBD effectively extends the LUMO orbitals and maintains a balance between hole and electron transport properties. This work aims to elucidate the experimental phenomena and establish a theoretical foundation for the development of high-mobility semiconductor materials.

An external electric field (EEF) exerts a great influence on geometry and electronic structure of organic semiconductors. The change in non-bonding properties of C-atoms in HOMO/LUMO under an EEF is related to the change in reorganization energy.

Three anthracene derivatives with a 2,6-diphenylanthracene core and C-, O-, and S-bridged alkyl chain substituents (BEPAnt, BOPAnt, and BSPAn) exhibit relatively balanced high luminescence and mobility properties, and can be candidates for organic light-emitting transistor device materials. The optoelectronic properties including charge transport and fluorescent properties of three anthracene derivatives were investigated via quantum chemistry calculations. The results show that BEPAnt and BOPAnt exhibit high hole mobility (3.60 and 1.35 cm(2) V-1 s(-1)) and blue emission fluorescence quantum yield (>60%). In addition, the growth morphology of crystals/films can affect their properties, especially charge transport behavior but is often overlooked in theoretical evaluation. Hence, the morphological evolution of their organic thin-film is characterized by the attachment energy (AE) model. The predicted morphologies for BEPAnt and BOPAnt are consistent with the shape of their single-crystal films using the physical vapor transport (PVT) technique. The phenomenon of in-plane growth ratios for BEPAnt and BOPAnt crystal facets is reproduced well using the AE model. Notably, symmetrical hydrogen bond interactions within and between crystal layers facilitate the formation of a large flat film such as BOPAnt, which is conducive to better performance of charge transport properties in the experiment. We hope that this study can clearly provide details on the driving forces that affect the crystal surface growth rate, and then provide valuable guidance for the design and regulation of organic semiconductor molecules with ideal crystal morphology.

High mobility has always been an important metric in the study of organic semiconductor materials (OSCs). Various external factors, including pressure, temperature, and light, have the potential to influence the mobility of OSCs. Pressure, in particular, can modify the intermolecular distance and molecular orbital, making it an ideal candidate for controlling carrier mobility and optimizing semiconductor device performance. However, the effect of pressure on the photoelectric behavior of organic molecules with different stacking patterns remains uncertain. To address this, we prepared a series of anthracene-based semiconductor molecules to predict the effect of hydrostatic pressure on the charge-transport properties through first-principles and multiscale computational simulations based on hopping and band transport mechanisms. Our findings indicate that the mobility of TIPSAntNa in one-dimensional (1D) pi-stacking is not consistently monotonic but rather reaches a peak at 5 GPa, which is attributed to the gradual increase in pressure-induced reorganization energy (lambda) and the periodic variation in transfer integral (V). Differently, for herringbone stacked crystals, the Vs increase with higher pressure, resulting in higher mobility under such conditions. This means that 1D pi-stacked organic molecules exhibit enhanced sensitivity to pressure, resulting in higher mobility at low pressures. Additionally, it is noteworthy that the appropriate pressure control can convert a p-type transport material into an n-type transport material. Consequently, our research provides valuable insights for achieving enhanced performance of OSCs by modulating pressure.

n Type organic semiconductor materials(OSCs) are essential in logic complementary circuits, but their related development has lagged behind relatively due to their poor air stability and low mobility. In this work, the charge transport properties of several typical n type OSCs naphthalene tetracarboxylic diimide(NDI) based on different pi-core extensions were analyzed by first principles simulation to elucidate the charge transport properties in term of the single-molecule structural features, intermolecular stacking modes, and intermolecular interactions, respectively. The results show that all of the studied molecules also have good air stability and exhibit electron transport properties. Among them, A2 with a long axis pi extension has a high electron affinity(EA) and the best air stability. Secondly, compared to NDI molecule, the reorganization energies of the NDI organic semiconductors with the long-axis/short-axis pi-extension were all reduced, but the origin for their decreased reorganization energy were found to be distinctly different according to the normal modes analysis. Compared to the A1 molecule, the vibrations of the A2 with the short axis pi-extension was effectively suppressed in the high -frequency region, whereas the vibrations of the A3 and A4 molecules extended along the long axis were suppressed in both the high and low -frequency regions, resulting in a reduction of the reorganization energy. Finally, the nearest -neighbour dimer stacking of studied molecular crystals was analyzed, and it was found that A3 and A4 have small short -axis sliping and behave as 2D electron transport materials, with 2D average electron mobility of ca. 0.06 and 0.15 cm(2)center dot V-1 center dot s(-1), respectively; while A2 has larger short -axis slip and thus behaves as 1D transport materials, with their 1D electron mobility as high as 0.96 cm(2)center dot V-1 center dot s(-1). In this paper, the relationship between molecular structure -molecular stacking patterns-electron transport properties of several typical n type OSCs NDI with different core structures was analyzed through theoretical computational simulations, which provides useful design ideas for the design of stable high-performance electron transport materials.

To date, the manipulation of intermolecular nonconjugation interactions in organic crystals is still a great challenge due to the complexity of weak intermolecular interactions. Here we designed molecules substituted by β-methylselenyl on naphtho[1,2-b:5,6-b']dithiophene and anthra[2,3-b:6,7-b']dithiophene, respectively (anti-β-MS-NDT, anti-β-MS-ADT), which together with anti-β-MS-BDT synthesized experimentally all exhibited 2D brickwork π-stacking. Moreover, their maximum molecular carrier mobilities reached 3.30 and 16.46 cm2 V-1 s-1. These results indicated that the substitution of β-methylselenyl could be a strategy to directionally adjust the parent herringbone stacking into 2D brickwork π-stacking. Hirshfeld surface analysis and symmetry-adapted perturbation theory (SAPT) were used to investigate the nonconjugated interactions in the pitched π-stacking formed by the β-methylthio-substituted acenedithiophene derivatives and the 2D brickwork π-stacking of the β-methylselenyl-substituted ones; wherein, the steric hindrance caused by the introduction of the substituents promoted Csp2-Csp2⋯π interactions to replace Csp2-H⋯π to stabilize the face-to-face stacking. Moreover, by calculating the decomposition energy of the intermediate state model of the molecular stacking mode that may exist in the replacement conversion process, it was found that the energy of this intermediate state was larger than that of the actual ones, finally confirming the inevitability of the actual existence in this stacking. In addition, because of the reduction in intensity of the special vibration modes, it could be found that the β-methylselenyl substitution showed better phonon assistance than β-methylthio substitution in terms of dynamic disorder. This study is a further step toward fully understanding the relationship between intermolecular interactions and regulation of the molecular stacking.

Organic semiconductors (OSCs) are widely used in flexible display, renewable energy, and biosensors, owing to their unique solid-state physical and optoelectronic properties. Among the abundant crystal library of OSCs, asymmetric aryl anthracene derivatives have irreplaceable advantages due to the interplay between their distinct π-conjugated geometry and molecular stacking as well as efficient light emission and charge transport properties that can be simultaneously utilized. However, the poor crystal stacking patterns of most asymmetric molecules limit their utility as excellent OSCs. Thus, it is crucial to clarify the structural features that enable the extremely ordered stacking and favorable electronic structure of asymmetric anthracene derivatives to become high-performance OSCs. This contribution investigates the charge transport properties of a series of asymmetric aryl anthracene derivatives to reveal the modulation factors of the molecular stacking modes and to explore the structural factors, which are beneficial to charge transport. The analysis demonstrated that the vinyl-linker facilitated the injection of hole carriers, and the alkynyl-linker effectively reduces the reorganization energy. Importantly, the linear polarizability and permanent dipole moment of a single molecule play a vital regulation to molecular stacking modes and the transfer integral of the dimer. The "head-to-head stacking" motif shows a compact stacking pattern and the maximum 2D anisotropic mobility more than 10 cm2 V-1 s-1. These findings sharpen our understanding of the charge transport properties in asymmetric organic semiconductors and are essential for developing a diverse range of high-performance OSC materials.

2,6-Diphenyl anthracene (2,6-DPA) is a well-known anthracene derivative with high hole mobility (34 cm2 V-1 s-1) among p-type organic semiconductors (OSCs). In contrast, three 2,6-dipyridyl anthracene (2,6-DPyA) molecules (ortho-, meta-, and para-pyridyl), which are isoelectronic to 2,6-DPA showed relatively low mobility in experiments. To explore the origin of different charge transport properties and gain new inspiration on the design of novel organic semiconductor materials, the intrinsic hole transport property of 2,6-DPA and three isomeric 2,6-DPyAs were theoretically investigated and compared by quantum-chemical methodology and molecular dynamics simulation. The calculated results indicate that the intrinsic mobility of 2,6-DPyA-b (meta-) is superior to that of 2,6-DPA (12.73 vs. 3.54 cm2 V-1 s-1). Furthermore, the possibility that 2,6-DPyA-b may be strongly affected by thermal fluctuations is excluded because of the strong intermolecular C-H⋯N interactions (H-bonds). In addition, the crystal growth morphology prediction is considered in depth by the attachment energy (AE) model. The prediction results demonstrate that the strong intermolecular H-bonds in 2,6-DPyA do not facilitate the formation of a large and regular crystal face but rather the production of many grains and grain boundaries, which is not conducive to the charge carrier transport. This study reflects the paradox of the H-bond in OSCs and highlights the indispensability of the mesoscopic crystal growth morphology prediction in identifying high performance OSC materials and the establishment of the relationship between microcosmic organic molecules and macroscopic device performance.

Scintillators have recently attracted increased attention because of their potential applications in various fields, such as medical imaging, security, and nondestructive inspection. However, the response time of commercial scintillators is normally in microseconds or milliseconds only, a property that restricts their practical applications in high-resolution and dynamic X-ray imaging. Here, we report Rb2AgCl3 crystals as an efficient scintillator material with ultrafast response time. The Rb2AgCl3 crystals were found to have a one-dimensional structure and a bright-orange emission peak at 580 nm and a quantum yield of 60.0%. Experimental and computational studies revealed that the strong emission might have originated from self-trapping excitons that resulted into large Stokes shifts and high quantum efficiency. Upon X-ray excitation, the Rb2AgCl3 crystals displayed a fast scintillation decay time of 9.5 ns and achieved a light yield of 18,300 photons MeV-1. The ratio of light yield to decay time could reach up to 1926 photons MeV- 1 ns-1, which was higher than that of existing commercial scintillators. As a scintillator, Rb2AgCl3 crystals are a promising material with potential applications in dynamic realtime imaging with a high spatial resolution owing to its nontoxicity, good stability, high light yield, and short decay time.

High-performance organic semiconductor materials based on the small aromatic anthracene-core and its derivatives develop comparatively slowly due to the lack of a profound understanding of the influence of chemical modifications on their charge-transfer properties. Herein, the electronic properties and the charge transport characteristics of several typical anthracene-based derivatives with aryl groups substituted at the 2,6-site are systematically investigated by multi-scale simulation methods including Molecular Dynamics (MD) simulation and the full quantum nuclear tunneling model in the framework of density functional theory (DFT). To elucidate the origin of different charge transport properties of these anthracene-based materials, analysis of the molecular stacking and noncovalent intermolecular interaction caused by different substituents was carried out. The results indicate that the electron and hole injection capabilities and the air oxidation stability of the anthracene derivatives are greatly improved when the size of the aryl substituent increases. In addition, the incorporation of 2,6-site aryl substituents can inhibit the stretching vibration of the anthracene-core during charge transport, and allow molecular packing along the long axis (a-axis of DPA and BDBFAnt, and c-axis of dNaAnt) with almost no slippage, and the main transport channels remain unchanged, exhibiting more isotropic 2D transport properties. It should be emphasized that the edge-to-face dimers with smallest dihedral angles are closest to the thermally stable dimer model, with relatively larger π-orbital distributions in transmission channels (dimer 1, 2) and the largest spatial overlap, resulting in the largest hole transfer integral in DPA (Vh1/h2 = 57 meV). Although the analysis of the thermal disorder effect shows a phonon scattering effect, the maximum hole mobility of the DPA molecule is still as high as 1.5 cm2 V-1 s-1.

Radioluminescence materials (scintillators) are widely investigated because of their potential application in many fields, such as medical imaging, security‐related techniques, and nondestructive inspection. However, the fabrication of scintillator materials with simultaneously fast response time, high absorption coefficient, and high light yield, as well as low toxicity is still a challenge. Herein, the synthesis of Cu(I)‐doped Cs2AgI3 single crystals (SCs) with a 1D crystal structure is presented. A bright blue‐green photoluminescence (PL) is observed after incorporating Cu+ into the Cs2AgI3 SCs under UV irradiation at room temperature. The PL quantum yield of the doped samples can reach up to 73% at a Cu+ concentration of 0.66%. Experimental and theoretical studies show that the blue‐green emission may originate from self‐trapped excitons, which is further verified by photophysical results from control experiments on pure Cs2AgI3 SCs. Upon X‐ray excitation, Cu‐doped SCs exhibit fast scintillation decay time (288 ns), high light yield (27 000 photons per MeV), and high absorption coefficient compared with the commercial product (CsI: Tl). These results suggest that Cu‐doped Cs2AgI3 is an ideal scintillator, which will be a promising candidate for potential application in dynamic real‐time imaging and radiation detection.