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# Space charge dynamics Of CF4 fluorinated LDPE samples from different fluorination conditions and their DC conductivities

Chen, Guanghui, Liu, Ning, Li, Ziyun, Chen, Qiang and Li, Shengtao (2017) Space charge dynamics Of CF4 fluorinated LDPE samples from different fluorination conditions and their DC conductivities. Materials Research Express, 4 (7), [075308].

Record type: Article

## Abstract

Taking advantage of plasma technology using mixing gas CF4/H2, a fluorination process was performed on LDPE samples in the present paper. Different exposure times and discharge voltage levels were applied to produce four different types of samples. It has been found that after fluorination, space charge injection is obviously suppressed. And with longer fluorination times and higher discharge voltage, injected homocharges are reduced. By employing x-ray photoelectron spectroscopy, new chemical groups of C–F bindings are confirmed to be introduced by fluorination process of the plasma treatment. The charge suppression effect can be explained as: surface traps introduced by fluorination will reduce the interface field at both electrodes. Moreover, for fluorinated samples, heterocharge emerges obviously under 30 kV $\text{m}{{\text{m}}^{-1}}$ , which are considered as charges ionized from degradation products of etching and/or lower weight molecular specifies. Through the conductivity measurements also performed at 30 kV $\text{m}{{\text{m}}^{-1}}$ , it is found that, for the fluorinated samples with the better charge blocking effect, the conductivity is lowered. However, the conductivity of the fluorinated sample with the lightest degree of fluorination is found to be higher than that of normal samples.

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Accepted/In Press date: 7 July 2017
e-pub ahead of print date: 7 July 2017
Published date: 31 July 2017

## Identifiers

Local EPrints ID: 432781
URI: http://eprints.soton.ac.uk/id/eprint/432781
PURE UUID: dab967db-c6d3-4999-a3ea-022502775fbc

## Catalogue record

Date deposited: 26 Jul 2019 16:30

## Contributors

Author: Guanghui Chen
Author: Ning Liu
Author: Ziyun Li
Author: Qiang Chen
Author: Shengtao Li