Pyroelectricity induced by spacehyphen;charge injection in polymer electrets

摘要

Coronahyphen;charged polypropylenehyphen;film electrets are reported to give a reversible shorthyphen;circuit electrical current when subjected to a change in temperature. This current varies as the time derivative of the temperature; we point out a linear dependence of the signal amplitude on the charge of the electret. We show that without specific assumptions concerning charge trapping, the sample expansion cannot account for this pyroelectric behavior. The results can be explained in terms of either a dipolar distribution or a noncentrosymmetry of the trapping centers.