scholarly journals An effective strategy to enhance the dielectric constant of organic semiconductors – CPDTTPD-based low bandgap polymers bearing oligo(ethylene glycol) side chains

2018 ◽  
Vol 6 (3) ◽  
pp. 500-511 ◽  
Author(s):  
Jeroen Brebels ◽  
Evgenia Douvogianni ◽  
Dries Devisscher ◽  
Raghavendran Thiruvallur Eachambadi ◽  
Jean Manca ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Ethylene Glycol ◽  
Organic Semiconductors ◽  
Dielectric Constants ◽  
Side Chains ◽  
Effective Strategy ◽  
Low Bandgap

Gradually increasing dielectric constants (up to 6.3) are obtained for a series of PCPDTTPD polymers.

scholarly journals Rational Design of Donor Acceptor Based Semiconducting Copolymers with High Dielectric Constant

2020 ◽  
Author(s):  
Aiswarya Abhisek Mohapatra ◽  
Yifan Dong ◽  
Puttaraju Boregowda ◽  
Ashutosh Mohanty ◽  
Aditya Sadhanala ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Rational Design ◽  
Dielectric Constants ◽  
Side Chains ◽  
Free Charge ◽  
Coulombic Interaction ◽  
Polymer Backbone ◽  
Donor Acceptor

<div> <div> <div> <p>An efficient photogeneration of free charge carriers has long been recognized as the paramount challenge in organic photovoltaic (OPV) devices. The low dielectric constant organic semiconductors fall short to reduce strong Coulombic interaction of tightly bound exciton and hence lead to a loss mechanism in OPVs due to charge-carrier recombination. To circumvent this problem, we adopt a strategy to enhance the dielectric constant of organic semiconductors by incorporating tetraethyleneglycol (TEG) side-chains. We report synthesis of three new semiconducting copolymers by combining thiophene substituted diketopyrrolopyrrole (TDPP) monomer with three other monomeric units with varying electron donating strength: benzodithiophene (BBT-3TEG-TDPP), TDPP (TDPP-3TEG-TDPP) and naphthalene diimide (PNDITEG-TDPP). BBT-3TEG-TDPP and PNDITEG-TDPP showed highest dielectric constants (~ 5) at 1MHz frequency suggesting efficient contribution of dipolar polarization from TEG side-chains. To understand the electronic contribution of the polymer backbone and the polarity of TEG side-chains, and the resulting enhancement of the dielectric constant, we further performed first-principles density functional theory calculations. Single-component organic solar cells (OSC) fabricated utilizing these polymers resulted in poor performance which is attributed to the absence of free charge generation. Furthermore, transient absorption spectroscopy studies show low exciton diffusion length as observed in donor-acceptor type conjugated polymers. Our results suggest that, the strategy of enhancing dielectric constant with polar side-chains is not sufficient to reduce Coulombic interaction between hole and electron in OSCs. </p> </div> </div> </div>

scholarly journals Rational Design of Donor Acceptor Based Semiconducting Copolymers with High Dielectric Constant

2020 ◽  
Author(s):  
Aiswarya Abhisek Mohapatra ◽  
Yifan Dong ◽  
Puttaraju Boregowda ◽  
Ashutosh Mohanty ◽  
Aditya Sadhanala ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Rational Design ◽  
Dielectric Constants ◽  
Side Chains ◽  
Free Charge ◽  
Coulombic Interaction ◽  
Polymer Backbone ◽  
Donor Acceptor

<div> <div> <div> <p>An efficient photogeneration of free charge carriers has long been recognized as the paramount challenge in organic photovoltaic (OPV) devices. The low dielectric constant organic semiconductors fall short to reduce strong Coulombic interaction of tightly bound exciton and hence lead to a loss mechanism in OPVs due to charge-carrier recombination. To circumvent this problem, we adopt a strategy to enhance the dielectric constant of organic semiconductors by incorporating tetraethyleneglycol (TEG) side-chains. We report synthesis of three new semiconducting copolymers by combining thiophene substituted diketopyrrolopyrrole (TDPP) monomer with three other monomeric units with varying electron donating strength: benzodithiophene (BBT-3TEG-TDPP), TDPP (TDPP-3TEG-TDPP) and naphthalene diimide (PNDITEG-TDPP). BBT-3TEG-TDPP and PNDITEG-TDPP showed highest dielectric constants (~ 5) at 1MHz frequency suggesting efficient contribution of dipolar polarization from TEG side-chains. To understand the electronic contribution of the polymer backbone and the polarity of TEG side-chains, and the resulting enhancement of the dielectric constant, we further performed first-principles density functional theory calculations. Single-component organic solar cells (OSC) fabricated utilizing these polymers resulted in poor performance which is attributed to the absence of free charge generation. Furthermore, transient absorption spectroscopy studies show low exciton diffusion length as observed in donor-acceptor type conjugated polymers. Our results suggest that, the strategy of enhancing dielectric constant with polar side-chains is not sufficient to reduce Coulombic interaction between hole and electron in OSCs. </p> </div> </div> </div>

Engineering dielectric constants in organic semiconductors

2017 ◽  
Vol 5 (15) ◽  
pp. 3736-3747 ◽  
Author(s):  
Ardalan Armin ◽  
Dani M. Stoltzfus ◽  
Jenny E. Donaghey ◽  
Andrew J. Clulow ◽  
Ravi Chandra Raju Nagiri ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Organic Semiconductors ◽  
Organic Semiconductor ◽  
Photovoltaic Device ◽  
Dielectric Constants ◽  
Optical Frequency ◽  
Generation Efficiency ◽  
Charge Generation

An optical-frequency dielectric constant of 4.6 leads to improved charge generation efficiency in an organic semiconductor homojunction photovoltaic device.

scholarly journals Comment on “investigation of dielectric constants of water in a nano-confined pore” by H. Zhu, F. Yang, Y. Zhu, A. Li, W. He, J. Huang and G. Li, RSC Adv., 2020, 10, 8628

RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 5179-5181
Author(s):  
Sayantan Mondal ◽  
Biman Bagchi
Keyword(s):  
Dielectric Constant ◽  
Dielectric Constants ◽  
Static Dielectric Constant ◽  
Inherent Anisotropy ◽  
Nanoconfined Water

Neglects of inherent anisotropy and distinct dielectric boundaries may lead to completely erroneous results. We demonstrate that such mistakes can give rise to gross underestimation of the static dielectric constant of cylindrically nanoconfined water.

Aqueous-Alcohol-Processable High-Mobility Semiconducting Copolymers with Engineered Oligo(ethylene glycol) Side Chains

2019 ◽  
Vol 32 (3) ◽  
pp. 1111-1119 ◽  
Author(s):  
Boseok Kang ◽  
Ziang Wu ◽  
Min Je Kim ◽  
Han Young Woo ◽  
Jeong Ho Cho
Keyword(s):  
Ethylene Glycol ◽  
High Mobility ◽  
Side Chains ◽  
Aqueous Alcohol

Low bandgap poly(thienylenemethine) derivatives bearing terarylene moieties in the side chains

2014 ◽  
Vol 5 (24) ◽  
pp. 6977-6989 ◽  
Author(s):  
Sangbum Ahn ◽  
Kazuki Yabumoto ◽  
Yongsoo Jeong ◽  
Kazuo Akagi
Keyword(s):  
Side Chains ◽  
Low Bandgap

Novel low bandgap poly(thienylenemethine) derivatives bearing terphenylene moieties in the side chains were synthesised. The bandgaps were controlled by introducing quinoidal structures into the benzonoidal main chains.

DIELECTRIC CONSTANT AND SEEBECK COEFFICIENT FOR SEMICONDUCTORS: THERMODYNAMIC AND DFT STUDIES

2013 ◽  
Vol 12 (06) ◽  
pp. 1350057 ◽  
Author(s):  
HSIU-YA TASI ◽  
CHAOYUAN ZHU
Keyword(s):  
Boundary Condition ◽  
Dielectric Constant ◽  
Seebeck Coefficient ◽  
Gas Phase ◽  
Present Method ◽  
Dielectric Constants ◽  
Semiconductor Materials ◽  
Electronic Polarizability ◽  
Seebeck Coefficients ◽  
Good Agreement

Dielectric constants and Seebeck coefficients for semiconductor materials are studied by thermodynamic method plus ab initio quantum density functional theory (DFT). A single molecule which is formed in semiconductor material is treated in gas phase with molecular boundary condition and then electronic polarizability is directly calculated through Mulliken and atomic polar tensor (APT) density charges in the presence of the external electric field. This electronic polarizability can be converted to dielectric constant for solid material through the Clausius–Mossotti formula. Seebeck coefficient is first simulated in gas phase by thermodynamic method and then its value divided by its dielectric constant is regarded as Seebeck coefficient for solid materials. Furthermore, unit cell of semiconductor material is calculated with periodic boundary condition and its solid structure properties such as lattice constant and band gap are obtained. In this way, proper DFT function and basis set are selected to simulate electronic polarizability directly and Seebeck coefficient through chemical potential. Three semiconductor materials Mg 2 Si , β- FeSi 2 and SiGe are extensively tested by DFT method with B3LYP, BLYP and M05 functionals, and dielectric constants simulated by the present method are in good agreement with experimental values. Seebeck coefficients simulated by the present method are in reasonable good agreement with experiments and temperature dependence of Seebeck coefficients basically follows experimental results as well. The present method works much better than the conventional energy band structure theory for Seebeck coefficients of three semiconductors mentioned above. Simulation with periodic boundary condition can be generalized directly to treat with doped semiconductor in near future.

scholarly journals A note on some further determinations of the dielectric constants of organic bodies and electrolytes at very low temperatures

1898 ◽  
Vol 62 (379-387) ◽  
pp. 250-266 ◽  
Keyword(s):  
Dielectric Constant ◽  
Low Temperatures ◽  
Tuning Fork ◽  
Dielectric Constants ◽  
The Past ◽  
Method Of Measurement ◽  
The Given ◽  
Past Summer

In several previous communications we have described the investigations made by us on the dielectric constants of various frozen organic bodies and electrolytes at very low temperatures. In these researches we employed a method for the measurement of the dielectric constant which consisted in charging and discharging a condenser, having the given body as dielectric, through a galvanometer 120 times in a second by means of a tuning-fork interrupter. During the past summer we have repeated some of these determinations and used a different method of measurement and a rather higher frequency. In the experiments here described we have adopted Nernst’s method for the measurement of dielectric constants, using for this purpose the apparatus as arranged by Dr. Nernst which belongs to the Davy-Faraday Laboratory.

Epitaxial Growth and Anisotropic Dielectric Properties of La-Doped Bi4Ti3O12 Thin Films

2007 ◽  
Vol 124-126 ◽  
pp. 177-180
Author(s):  
Jang Sik Lee ◽  
Q.X. Jia
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Bottom Electrode ◽  
Dielectric Constants ◽  
The Other ◽  
Field Range ◽  
Anisotropic Dielectric ◽  
Dielectric Nonlinearity ◽  
La Doped

To investigate the anisotropic dielectric properties of layer-structured bismuth-based ferroelectrics along different crystal directions, we fabricate devices along different crystal orientations using highly c-axis oriented Bi3.25La0.75Ti3O12 (BLT) thin films on (001) LaAlO3 (LAO) substrates. Experimental results have shown that the dielectric properties of the BLT films are highly anisotropic along different crystal directions. The dielectric constants (1MHz at 300 K) are 358 and 160 along [100] and [110], respectively. Dielectric nonlinearity is also detected along these crystal directions. On the other hand, a much smaller dielectric constant and no detectable dielectric nonlinearity in a field range of 0-200 kV/cm are observed for films along [001] when c-axis oriented SRO is used as the bottom electrode.

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