On the impact of isomer structure and packing disorder in thienoacene organic semiconductors

2016 ◽  
Vol 4 (18) ◽  
pp. 4040-4048 ◽  
Author(s):  
Karl J. Thorley ◽  
Chad Risko

Using benzodithiophene as a model compound, the concept of the disordermer is introduced to discuss how intermolecular isomerism in the solid state can result in a wide range of available molecular packing arrangements that in turn influence the magnitude of the electronic coupling, a key parameter of importance to the performance of organic semiconductors.

2016 ◽  
Vol 4 (17) ◽  
pp. 3825-3832 ◽  
Author(s):  
Karl J. Thorley ◽  
Chad Risko

The varied topography of intermolecular electronic coupling offers a wide-ranging materials design landscape to engineer solid-state molecular packing for new generations of organic semiconductors.


2003 ◽  
Vol 771 ◽  
Author(s):  
Antonio Facchetti ◽  
Myung-Han Yoon ◽  
Howard E. Katz ◽  
Melissa Mushrush ◽  
Tobin J. Marks

AbstractOrganic semiconductors exhibiting complementary-type carrier mobility are the key components for the development of the field of “gplastic electronics” We present here a novel series of α,ω- and isomerically pure ββ'-diperfluorohexyl-substituted thiophene and study the impact of fluoroalkyl substitution and conjugation length vis-a-vis the corresponding fluorinefree analogues. Trends between the fluorinated and fluorine-free families in molecular packing, HOMO-LUMO gap, and π-π interactions are found to be strikingly similar. TFT measurements indicate that all members of the fluorinated series are n-type semiconductors


Author(s):  
Andrey Sosorev ◽  
Dmitry Dominskiy ◽  
Ivan Chernyshov ◽  
Roman Efremov

Chemical versatility of organic semiconductors provides nearly unlimited opportunities for tuning their electronic properties. However, despite decades of research, relationship between molecular structure, molecular packing and charge mobility in these materials remains poorly understood. This reduces the search for high-mobility organic semiconductors to the inefficient trial-and-error approach. For clarifying the abovementioned relationship, investigations of the effect of small changes in the chemical structure on OSs properties are particularly important. In this study, we address computationally the impact of substitution of C-H atom pairs by nitrogen atoms (N-substitution) on molecular properties, molecular packing and charge mobility of crystalline oligoacenes. Besides of decreasing frontier molecular orbital levels, N-substitution dramatically alters molecular electrostatic potential yielding pronounced electron-rich and electron-deficient areas. These changes in the molecular electrostatic potential strengthen face-to-face and edge-to-edge interactions in the corresponding crystals and result in the crossover from the herringbone packing motif to π-stacking. When the electron-rich and electron-deficient areas are large, sharply defined and, probably, have certain symmetry, charge mobility increases up to 3-4 cm2V-1s-1. The results obtained highlight the potential of azaacenes for application in organic electronic devices and are expected to facilitate rational design of organic semiconductors for steady improvement of organic electronics.


2022 ◽  
Author(s):  
Yan Zeng ◽  
Guangchao Han ◽  
Yuanping Yi

Electrical conductivity is one of the key parameters for organic thermoelectrics and depends on both the concentration and mobility of charge carriers. To increase the carrier concentration, molecular dopants have to be added into organic semiconductor materials, whereas the introduction of dopants can influence the molecular packing structures and hence carrier mobility of the organic semiconductors. Herein, we have theoretically investigated the impact of different n-doping mechanisms on molecular packing and electron transport properties by taking N-DMBI-H and Q-DCM-DPPTT respectively as representative n-dopant and molecular semiconductor. The results show that when the doping reactions and charge transfer spontaneously occur in the solution at room temperature, the oppositely charged dopant and semiconductor molecules will be tightly bound to disrupt the semiconductor to form long-range molecular packing, leading to a substantial decrease of electron mobility in the doped film. In contrast, when the doping reactions and charge transfer are activated by heating the doped film, the molecular packing of the semiconductor is slight affected and hence the electron mobility remains quite high. This work indicates that thermally-activated n-doping is an effective way to achieve both high carrier concentration and high electron mobility in n-type organic thermoelectric materials.


2016 ◽  
Vol 55 (17) ◽  
pp. 5206-5209 ◽  
Author(s):  
Zongpeng Zhang ◽  
Lang Jiang ◽  
Changli Cheng ◽  
Yonggang Zhen ◽  
Guangyao Zhao ◽  
...  

2016 ◽  
Vol 195 ◽  
pp. 215-236 ◽  
Author(s):  
Jacob Spencer ◽  
Laura Scalfi ◽  
Antoine Carof ◽  
Jochen Blumberger

We investigate the performance of fewest switches surface hopping (SH) in describing electron transfer (ET) for a molecular donor–acceptor system. Computer simulations are carried out for a wide range of reorganisation energy (λ), electronic coupling strength (Hab) and driving force using our recently developed fragment orbital-based SH approach augmented with a simple decoherence correction. This methodology allows us to compute SH ET rates over more than four orders of magnitude, from the sub-picosecond to the nanosecond time regime. We find good agreement with semi-classical ET theory in the non-adiabatic ET regime. The correct scaling of the SH ET rate with electronic coupling strength is obtained and the Marcus inverted regime is reproduced, in line with previously reported results for a spin-boson model. Yet, we find that the SH ET rate falls below the semi-classical ET rate in the adiabatic regime, where the free energy barrier is in the order of kBT in our simulations. We explain this by first signatures of non-exponential population decay of the initial charge state. For even larger electronic couplings (Hab = λ/2), the free energy barrier vanishes and ET rates are no longer defined. At this point we observe a crossover from ET on the vibronic time scale to charge relaxation on the femtosecond time scale that is well described by thermally averaged Rabi oscillations. The extension of the analysis from the non-adiabatic limit to large electronic couplings and small or even vanishing activation barriers is relevant for our understanding of charge transport in organic semiconductors.


2016 ◽  
Vol 128 (17) ◽  
pp. 5292-5295 ◽  
Author(s):  
Zongpeng Zhang ◽  
Lang Jiang ◽  
Changli Cheng ◽  
Yonggang Zhen ◽  
Guangyao Zhao ◽  
...  

2020 ◽  
Vol 21 (16) ◽  
pp. 5654
Author(s):  
Andrey Sosorev ◽  
Dmitry Dominskiy ◽  
Ivan Chernyshov ◽  
Roman Efremov

The chemical versatility of organic semiconductors provides nearly unlimited opportunities for tuning their electronic properties. However, despite decades of research, the relationship between molecular structure, molecular packing and charge mobility in these materials remains poorly understood. This reduces the search for high-mobility organic semiconductors to the inefficient trial-and-error approach. For clarifying the abovementioned relationship, investigations of the effect of small changes in the chemical structure on organic semiconductor properties are particularly important. In this study, we computationally address the impact of the substitution of C-H atom pairs by nitrogen atoms (N-substitution) on the molecular properties, molecular packing and charge mobility of crystalline oligoacenes. We observe that besides decreasing frontier molecular orbital levels, N-substitution dramatically alters molecular electrostatic potential, yielding pronounced electron-rich and electron-deficient areas. These changes in the molecular electrostatic potential strengthen face-to-face and edge-to-edge interactions in the corresponding crystals and result in the crossover from the herringbone packing motif to π-stacking. When the electron-rich and electron-deficient areas are large, sharply defined and, probably, have a certain symmetry, calculated charge mobility increases up to 3–4 cm2V−1s−1. The results obtained highlight the potential of azaacenes for application in organic electronic devices and are expected to facilitate the rational design of organic semiconductors for the steady improvement of organic electronics.


2009 ◽  
Vol 8 (1) ◽  
Author(s):  
Chalimah .

eamwork is becoming increasingly important to wide range of operations. It applies to all levels of the company. It is just as important for top executives as it is to middle management, supervisors and shop floor workers. Poor teamwork at any level or between levels can seriously damage organizational effectiveness. The focus of this paper was therefore to examine whether leadership practices consist of team leader behavior, conflict resolution style and openness in communication significantly influenced the team member’s satisfaction in hotel industry. Result indicates that team leader behavior and the conflict resolution style significantly influenced team member satisfaction. It was surprising that openness in communication did not affect significantly to the team members’ satisfaction.


2021 ◽  
Author(s):  
Ekaterina Mosolova ◽  
Dmitry Sosin ◽  
Sergey Mosolov

During the COVID-19 pandemic, healthcare workers (HCWs) have been subject to increased workload while also exposed to many psychosocial stressors. In a systematic review we analyze the impact that the pandemic has had on HCWs mental state and associated risk factors. Most studies reported high levels of depression and anxiety among HCWs worldwide, however, due to a wide range of assessment tools, cut-off scores, and number of frontline participants in the studies, results were difficult to compare. Our study is based on two online surveys of 2195 HCWs from different regions of Russia during spring and autumn epidemic outbreaks revealed the rates of anxiety, stress, depression, emotional exhaustion and depersonalization and perceived stress as 32.3%, 31.1%, 45.5%, 74.2%, 37.7% ,67.8%, respectively. Moreover, 2.4% of HCWs reported suicidal thoughts. The most common risk factors include: female gender, nurse as an occupation, younger age, working for over 6 months, chronic diseases, smoking, high working demands, lack of personal protective equipment, low salary, lack of social support, isolation from families, the fear of relatives getting infected. These results demonstrate the need for urgent supportive programs for HCWs fighting COVID-19 that fall into higher risk factors groups.


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