scholarly journals Polymer Dielectric Materials

10.5772/50638 ◽  
2012 ◽  
Author(s):  
Zulkifli Ahmad
2014 ◽  
Vol 14 (3) ◽  
pp. 914-920 ◽  
Author(s):  
Jian-Yu Shih ◽  
Wen-Chun Huang ◽  
Cheng-Ta Ko ◽  
Zheng Yang ◽  
Sheng-Hsiang Hu ◽  
...  

2011 ◽  
Vol 1285 ◽  
Author(s):  
Gamal A. W. Abbas ◽  
Donna Cheng ◽  
Kanad Mallik ◽  
Hazel E. Assender

ABSTRACTWe report our fabrication of pentacene field effect transistors (FETs) based on a vacuum processed and e-beam cured polymer electrolyte (i.e., tripropylene glycol diacrylate (TRPGDA)) as a gate dielectric layer on flexible wide web substrates. The deposition of the semiconductor and gate insulator layers is carried out in Oxford's roll-to-roll vacuum web processing facility and could be combined in-line with roll-to-roll pattern metallization. The aim of the work is to demonstrate the ability to create all-evaporated transistors, exploiting the kind of technologies at present extensively used in the food packaging industry, for example, in which all layers can be deposited at high web speeds. Ours is a room temperature and a solvent-free method with an ultrahigh deposition rate (web speeds in excess of 100 m/min are possible).The performance of the pentacene and the polymer dielectric materials within devices was investigated, demonstrating (1) the ability to deposit good quality pentacene layers in the roll-to-roll environment and (2) the importance of the e-beam curing conditions of the dielectric layer on the performance of the organic FET devices. This deposition route creates a smooth, pin-hole-free dielectric layer as it is deposited onto the substrate as a monomeric liquid, before curing, and there is no mass-loss such as in solvent-based deposition processes. These devices have a 250 μm channel length and an aspect ratio of 16. No self-assembled monolayer (SAM) or other surface modification had been applied to the insulator layer to achieve these properties.The tuning of the transistors' operating voltage and output characteristics was feasible through the ease of control of the polymer dielectric thickness achieving a threshold voltage of less than 10 V. On/off ratio in excess of 103, and mobility = 0.1 cm2V-1s-1 have been achieved.The ability to integrate such a high deposition rate polymer process, into a single step, multilayer, vacuum deposition process with conventional vacuum deposition sources provides a possible route to low cost and large area electronic device processing.


Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yuhao Shi ◽  
Yingkai Zheng ◽  
Jialiang Wang ◽  
Ran Zhao ◽  
Tao Wang ◽  
...  

Organic field-effect transistors (OFETs) are of the core units in organic electronic circuits, and the performance of OFETs replies critically on the properties of their dielectric layers. Owing to the intrinsic flexibility and natural compatibility with other organic components, organic polymers, such as poly(vinyl alcohol) (PVA), have emerged as highly interesting dielectric materials for OFETs. However, unsatisfactory issues, such as hysteresis, high subthreshold swing, and low effective carrier mobility, still considerably limit the practical applications of the polymer-dielectric OFETs for high-speed, low-voltage flexible organic circuits. This work develops a new approach of using supercritical CO2 fluid (SCCO2) treatment on PVA dielectrics to achieve remarkably high-performance polymer-dielectric OFETs. The SCCO2 treatment is able to completely eliminate the hysteresis in the transfer characteristics of OFETs, and it can also significantly reduce the device subthreshold slope to 0.25 V/dec and enhance the saturation regime carrier mobility to 30.2 cm2 V−1 s−1, of which both the numbers are remarkable for flexible polymer-dielectric OFETs. It is further demonstrated that, coupling with an organic light-emitting diode (OLED), the SCCO2-treated OFET is able to function very well under fast switching speed, which indicates that an excellent switching behavior of polymer-dielectric OFETs can be enabled by this SCCO2 approach. Considering the broad and essential applications of OFETs, we envision that this SCCO2 technology will have a very broad spectrum of applications for organic electronics, especially for high refresh rate and low-voltage flexible display devices.


2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.


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