Electrical Conductivity Of Organic Semiconductors Research Articles

Carbon Quantum Dots Confined into Covalent Triazine Frameworks for Efficient Overall Photocatalytic H2O2 Production

AbstractPorous organic polymers have an outstanding performance in the field of photocatalysis with the advantage of diverse structure composition and purposeful molecular design. However, the inherent high impedance and poor electrical conductivity of organic semiconductors still restrict the charge transfer efficiency and thus discount the photocatalytic performance. Herein, the study reports a highly conductive covalent triazine framework (CTF) loading carbon quantum dots (CQDs) into porous as electron transport medium. The addition of CQDs (0.5 wt%) can enhance the electronic conductivity of CTF by tenfold. In addition, the as‐prepared CQD‐CTFs express much‐promoted charge separation and transfer efficiency. Furthermore, the embedded CQDs can improve the oxidization capacity and increase the affinity of H+ due to the more negative zeta potential. The enhanced oxidizing ability and increased H+ affinity are positive for water oxidation reaction (WOR) and oxygen reduction reaction (ORR) process in hydrogen peroxide (H2O2) generation, respectively. The optimized CQD‐CTF exhibits a high H2O2 generation rate of up to 1036 µmol g−1 h−1 in pure water without any sacrificial agent under visible light, which is 4.6 times than pristine CTF. This work provides a new idea for efficient H2O2 production of organic semiconductors.

State-of-Matter-Dependent Charge-Transfer Interactions between Planar Molecules for Doping Applications

Controlling the electrical conductivity of organic semiconductors is a key asset for organic electronics, nowadays realized mostly by molecular dopants. Two doping mechanisms have been reported – c...

Understanding electrical-thermal transport characteristics of organic semiconductors: Violation of Wiedemann-Franz law

Organic semiconductors exhibit plenty of attractive properties for use as thermoelectric elements. A comprehensive understanding for the electrical-thermal transport characteristics is crucial to design and fabricate the thermoelectric device. We proposed a theoretical model to investigate the electrical conductivity and the electronic thermal conductivity of organic semiconductors based on the hopping transport mechanism. The electrical-thermal transport characteristics of organic semiconductors have been analyzed in detail and compared with the experimental results and Monte Carlo simulation. The Wiedemann-Franz law, connecting the electronic thermal conductivity to the electrical conductivity of organic semiconductors, is generally found to be strongly violated under the effect of temperature, carrier concentration, energetic disorder and electric field.

Chemical Self-Doping of Organic Nanoribbons for High Conductivity and Potential Application as Chemiresistive Sensor.

Intrinsically low electrical conductivity of organic semiconductors hinders their further development into practical electronic devices. Herein, we report on an efficient chemical self-doping to increase the conductivity through one-dimensional stacking arrangement of electron donor-acceptor (D-A) molecules. The D-A molecule employed was a 1-methylpiperidine-substituted perylene tetracarboxylic diimide (MP-PTCDI), of which the methylpiperidine moiety is a strong electron donor, and can form a charge transfer complex with PTCDI (acting as the acceptor), generating anionic radical of PTCDI as evidenced in molecular solutions. Upon self-assembling into nanoribbons through columnar π-π stacking, the intermolecular charge transfer interaction between methylpiperidine and PTCDI would be enhanced, and the electrons generated are delocalized along the π-π stacking of PTCDIs, leading to enhancement in conductivity. The conductive fiber materials thus produced can potentially be used as chemiresistive sensor for vapor detection of electron deficient chemicals such as hydrogen peroxide, taking advantage of the large surface area of nanofibers. As a major component of improvised explosives, hydrogen peroxide remains a critical signature chemical for public safety screening and monitoring.

Charge transfer in and conductivity of molecularly doped thiophene‐based copolymers

ABSTRACTThe electrical conductivity of organic semiconductors can be enhanced by orders of magnitude via doping with strong molecular electron acceptors or donors. Ground‐state integer charge transfer and charge‐transfer complex formation between organic semiconductors and molecular dopants have been suggested as the microscopic mechanisms causing these profound changes in electrical materials properties. Here, we study charge‐transfer interactions between the common molecular p‐dopant 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane and a systematic series of thiophene‐based copolymers by a combination of spectroscopic techniques and electrical measurements. Subtle variations in chemical structure are seen to significantly impact the nature of the charge‐transfer species and the efficiency of the doping process, underlining the need for a more detailed understanding of the microscopic doping mechanism in organic semiconductors to reliably guide targeted chemical design. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 58–63

On the Meyer-Neldel rule in the electrical conductivity of organic semiconductors

On the Meyer-Neldel rule in the electrical conductivity of organic semiconductors

Some problems concerning electrical conductivity of organic semiconductors

Some problems concerning electrical conductivity of organic semiconductors

Electrical Conductivity of Organic Semiconductors at High Pressure

Abstract In order to study the effect of high pressure on the electrical conductivity of organic semiconductors, the band structure of the anthracene crystal has been calculated at atmospheric pressure and also at 160 kilobars, using the treatment of the tight-binding approximation. The total band widths of both electrons and holes at 160 kilobars are 5∼6 times as large as those at atmospheric pressure. Although the mobilities of both carriers, on the whole, increase in magnitude by several tens times at 160 kilobars, the sharp drop in the resistivity at high pressure may be due mostly to the great increase in the concentrations of the charge carriers (103∼104 times).