Charge distribution and transport in polymers

Abstract

Experimental work on charge distributions and charge transport in polymer films is reviewed. For studying the charge distributions in the thickness dimension, thermal or acoustic techniques are used with resolutions down to N 1 pm. The polymer samples usually are charged with corona, electron beam or thermal methods. Observation of the change of charge and polarization distributions with time allows one to draw conclusions about charge transport and charge injection phenomena. In some cases theoretical models have been established, based on excess-charge drift due to a finite carrier mobility and on charge compensation due to intrinsic or radiation-induced conductivity Other models are concerned with the interaction of injected or intrinsic space charge with a dipole polarization. Comparisons of measured and calculated charge distributions and their change with time show the applicability of these models and shed new light on charge trapping and charge transport phenomena.

Influence of thermal treatment and residues on space charge accumulation in XLPE for DC power cable application

“…It is generally concluded that such space charge may result from electrons (and holes) injection from the electrodes and electric field assisted ionization of the impurities in the material or from an inhomogeneous polarization [4][5][6][7][8][9][10]. With the success of space charge measurement on the film samples, attempts had also been made to apply the same techniques (mostly the PEA) in extruded polymer insulated power cables to study the space charge behaviour in cable geometry [11][12][13].…”

Energy harvesting study on single and multilayer ferroelectret foams under compressive force

“…FERROELECTRET is a thin and flexible cellular polymer foam that can store charges in its internal voids [1][2][3][4], thus being able to generate electric pulse under mechanical deformation such as compression and bending [5][6]. Due to its high piezoelectric voltage constant g 33 [7], ferroelectret has already been used extensively in sensor applications, such as blood pressure pulse transducer [8], touch sensor [9], ultrasonic transducer [10], prosthetic skin [11], and accelerometer [12].…”

Models of bipolar charge transport in polyethylene

“…Nevertheless, the space charge accumulation and the related trapping-detrapping phenomena are still poorly understood. Over recent decades, a great deal of effort has been expended in developing experimental tools for space charge characterization, 2-6 in measuring space charges profiles, [7][8][9] or in identifying the different kinds of charges. 10,11 Meanwhile, only a few attempts have been made to provide some model description of these experimental results.…”