Ural Federal University: Scientists Synthesized Polymer Films with Improved Dielectric Properties

An international team of scientists has improved polymer films, the basis for organic electronic components. The new material is promising for increasing the capacity in lithium polymer batteries, solar cells, and modernization of organic field-effect transistors. The description and results of the study are published in the Optik journal.

Organic electronics use organic materials to manufacture microcircuits and other electronic devices. Polymeric materials are used as semiconductors in such electronics and replace traditional electronic components based on silicon, copper, etc.

In particular, polyvinyl alcohol (PVA) polymer films are highly dielectric and charge-accumulating. They are used in lithium polymer batteries and capacitors, organic light super-capacitors emitting diodes (OLED), and solar cells. But they are still inferior to traditional silicon-based batteries in terms of energy storage efficiency. The group of scientists figured out how to make the PVS film more energy-efficient by adding another polymer – polyethylene glycol (PEG) – to its composition.

“The energy capacity of batteries directly depends on the dielectric permittivity of the polymer film. We analyzed how the dielectric properties of the PVS film change when PEG is added in different concentrations – 1, 3, 5, 10, 15, and 20 %. Impedance spectroscopy analysis showed that even at a one-percent concentration of PEG in the composition, the film’s ability to accumulate electricity increases several times. Consequently, the use of a mixture of PVS and PEG will increase the electrical capacity of lithium polymer batteries used in cell phones, digital devices, and, in particular, hybrid electric cars,” explains Ahmed Henaish, senior researcher at the UrFU Nanomaterials and Nanotechnologies Research and Education Center.

The improved polymer mixture can also be used in other organic electronic elements. For example, thanks to its new composition current losses in organic field effect transistors (OFET) are reduced.

“A feature of the field effect transistor is its low power consumption at fairly high currents. Now there is an increased interest in the application of OFET in new industrial devices. However, organic transistors still have a number of drawbacks, the elimination of which depends, among other things, on improving the properties of polymer materials,” adds Ahmed Henaish.

Researchers from Nanotech Research and Education Center, UrFU (Russia), and Tanta University (Egypt) worked on the synthesis of the films. In the future, the researchers plan to study the dielectric properties of thin polymeric nanocomposites made of PVS with aluminum addition.