Title :
Electret properties of polymer films deposited by vacuum evaporation
Author :
Fedosov, Sergai ; Zadorozhny, Vasili ; Sergeeva, Alexandra
Author_Institution :
Odessa Technol. Inst., USSR
Abstract :
It has been shown that the vacuum evaporation technique can be used to produce thin polymer electrets. Thin films (2-7 μm) of PE (polyethylene), PTFE (polytetrafluoroethylene), and PVDF (polyvinylidenefluoride) were deposited by the electron-beam method. The secondary polymerization was activated either thermally (5-200°C) or by electron irradiation (0.6 keV). It was found that the electron irradiation of PE and PTFE films causes defects. Defects in PE acted as shallow traps, while the deep trapping of injected charge carriers took place at cross-links. The pyro-coefficient and the level of the residual polarization in evaporated PVDF films were about two times lower than those of conventional films
Keywords :
dielectric polarisation; dielectric thin films; electrets; electron beam effects; electron traps; hole traps; polymer films; pyroelectricity; vacuum deposited coatings; 5 to 200 degC; PE; PTFE; PVDF; cross-links; deep trapping; defects; electret; electron irradiation; electron-beam method; injected charge carriers; polyethylene; polymer films; polytetrafluoroethylene; polyvinylidenefluoride; pyro-coefficient; residual polarization; secondary polymerization; shallow traps; thermal activation; vacuum evaporation; Aluminum; Corona; Dielectric measurements; Electrets; Electrons; Heating; Plastic films; Polyethylene; Polymer films; Substrates;
Conference_Titel :
Electrets, 1991. (ISE 7) Proceedings., 7th International Symposium on (Cat. No.91CH3029-6)
Conference_Location :
Berlin
Print_ISBN :
0-7803-0112-9
DOI :
10.1109/ISE.1991.167221
