Polarization and Space Charge Distribution in Thermally Poled Polyethylene and a Comparison with Polyvinylidene Fluoride

Electroded and annealed polyethylene fi lms were thermally poled and the recently developed Laser Intensity Modulation Method (LIMM) was used to measure the spatial distributions of both polarization and space charge through the thickness of the samples. Polarization due to the orientation of impurity dipoles and trapped space charge interacted in a complex manner to produce the pyroelectric currents excited by laser beam heating of the electrets. Comparisons are made with results obtained on thermally poled polyvinylidene fluoride.