scholarly journals Glass transition temperature prediction of disordered molecular solids

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kun-Han Lin ◽  
Leanne Paterson ◽  
Falk May ◽  
Denis Andrienko
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Semiconductors ◽  
Absolute Error ◽  
Organic Light Emitting Diodes ◽  
Molecular Solids ◽  
Reliable Prediction ◽  
Light Emitting ◽  
Molecular Ordering

AbstractGlass transition temperature, Tg, is the key quantity for assessing morphological stability and molecular ordering of films of organic semiconductors. A reliable prediction of Tg from the chemical structure is, however, challenging, as it is sensitive to both molecular interactions and analysis of the heating or cooling process. By combining a fitting protocol with an automated workflow for forcefield parameterization, we predict Tg with a mean absolute error of ~20 °C for a set of organic compounds with Tg in the 50–230 °C range. Our study establishes a reliable and automated prescreening procedure for the design of amorphous organic semiconductors, essential for the optimization and development of organic light-emitting diodes.

Anomalous Temperature Dependence of Solvent-Enhanced Dye Diffusion In Polymer Films

2002 ◽  
Vol 725 ◽  
Author(s):  
T. Graves-Abe ◽  
F. Pschenitzka ◽  
J.C. Sturm
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Temperature Dependence ◽  
Polymer Film ◽  
Light Emitting Diode ◽  
Solvent Vapor ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Thermally Driven

AbstractOne promising method to pattern full color polymer Organic Light-Emitting Diode (OLED) displays is to print dye from a pre-patterned organic film onto a spin-cast polymer and then diffuse the dye into the film at room temperature in a solvent vapor environment. This method utilizes the well-known tendency for a polymer film to absorb solvent vapor, which depresses the glass transition temperature of the polymer and dramatically increases diffusion the dye. In this work, we have studied the temperature dependence of this process. The dye coumarin 6 (C6) was transferred onto films consisting of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)- 1,3,4-oxadiazole (PBD) mixed with the polymer poly(9-vinylcarbazole) (PVK). Samples were then placed on a heated stage in a chamber and exposed to acetone vapor to diffuse the C6 into the polymer film. The profile of the diffused dye was determined by depthdependent photoluminescence measurements and Secondary Ion Mass Spectroscopy. We observed that the amount of diffused dye decreased at higher temperatures, in contrast to conventional thermally-driven diffusion. The results are understood by noting that the decrease in the polymer glass-transition temperature and the corresponding rapid increase in dye diffusivity depend on the quantity of solvent absorbed by the polymer, which decreases as the temperature of the polymer is raised.

Poly(Binaphthalenevinylene-alt-Phenylenevinylene) Derivatives: Novel Luminescent Polymers for Light-Emitting Devices

1999 ◽  
Vol 598 ◽  
Author(s):  
Lixin Zheng ◽  
Xuezhong Jiang ◽  
Michelle S. Liu ◽  
Alex K-Y. Jen
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Model Compound ◽  
Condensation Reaction ◽  
Spectral Characteristics ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Luminescent Polymers

ABSTRACTNovel conjugated light-emitting polymers were synthesized via a Wittig-Horner condensation reaction between a binaphthyl dicarbaldehyde and a series of electron-rich or electron-deficient aryl diphosphonates. After comparing these materials with the model compound, 4c, it was revealed that the introduction of a twisted, non-coplanar binaphthyl structure provided an effective approach for tailoring the spectral characteristics of the polymers and improving their solubility and thermal stability (glass transition temperature, Tg, 200°C). Furthermore, the band structures of the polymers could be fine-tuned by changing the electronic properties of the bridging aromatic units. The electroluninescence (EL) and device characteristics were also reported in this paper.

Blue phosphorescent organic light-emitting devices based on carbazole/thioxanthene-S,S-dioxide with a high glass transition temperature

2015 ◽  
Vol 3 (24) ◽  
pp. 6192-6199 ◽  
Author(s):  
Young Pyo Jeon ◽  
Kyu Sung Kim ◽  
Kyeong Kyun Lee ◽  
In Kyu Moon ◽  
Dong Chul Choo ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Host Material ◽  
High Glass Transition Temperature ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
Blue Phosphorescent

A bipolar host material for blue organic light-emitting devices was synthesized by incorporating electron-donating carbazole and electron-accepting thioxanthene-S,S-dioxide into one molecule using a solventless green reaction.

Prediction of Glass Transition Temperature of Polymer by Support Vector Regression

2012 ◽  
Vol 455-456 ◽  
pp. 436-442
Author(s):  
J.F. Pei ◽  
C.Z. Cai ◽  
X.J. Zhu ◽  
G.L. Wang ◽  
B. Yan
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Support Vector Regression ◽  
Density Functional ◽  
Absolute Error ◽  
Percentage Error ◽  
Support Vector ◽  
Quantum Chemical Descriptors ◽  
Leave One Out

. Based on two quantum chemical descriptors (the thermal energy Ethermal and the total energy of the whole system EHF) calculated from the structures of the repeat units of polyacrylamides by density functional theory (DFT), the support vector regression (SVR) approach combined with particle swarm optimization (PSO), is proposed to establish a model for prediction of the glass transition temperature (Tg) of polyacrylamides. The prediction performance of SVR was compared with that of multivariate linear regression (MLR). The results show that the mean absolute error (MAE=4.65K), mean absolute percentage error (MAPE=1.28%) and correlation coefficient (R2=0.9818) calculated by leave-one–out cross validation (LOOCV) via SVR models are superior to those achieved by QSPR (MAE=14.25K, MAPE=4.39% and R2=0.9211) and QSPR-LOO (MAE=17.01K, MAPE=5.66% and R2=0.8823) models for the identical samples, respectively. The prediction results strongly demonstrate that the modeling and generalization abilities of SVR model consistently surpass those of QSPR and QSPR-LOO models. It is revealed that the established SVR model is more suitable to be used for prediction of the Tg values for unknown polymers possessing similar structure than the conventional MLR approach. These suggest that SVR is a promising and practical methodology to predict the glass transition temperature of polyacrylamides.

A saddle-shaped o-tetraphenylene based molecular semiconductor with high glass transition temperature for perovskite solar cells

2021 ◽  
Author(s):  
Jianan Wang ◽  
Xinrui Xie ◽  
Yaohang Cai ◽  
Lifei He ◽  
Yi Yuan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Semiconductors ◽  
Perovskite Solar Cells ◽  
High Glass Transition Temperature ◽  
Molecular Semiconductor ◽  
Molecular Semiconductors

The application of exotic conjugated skeletons in organic semiconductors is alluring due to the topology related optoelectronic peculiarity. In this paper we explore the design of molecular semiconductors starting from...

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