Thermally stimulated depolarization current characteristics of Kapton‐H electrets are studied in the temperature range 303 to 573 K as functions of the polarizing field (133.3 to 500.0 kV cm−1), polarizing temperature (333 to 453 K), polarizing time (2.7 × 103 to 16.2 × 103 s), specimen thickness (2.5 × 106 to 12.5 × 106 nm), heating rate (0.017 to 0.10 K s−1), and storage time (0 to 720 h). The TSDC spectra comprise three maxima in all, namely, β, α, and ρ with their respective locations around 373, 453, and 553 K. These are attributed to dipole‐orientation, motion of space charges, and surface charge injection, respectively. A shoulder (β′) emerging around 343 K is suggested to be akin to the main β‐peak. The space‐charge peak is found to be more sensitive to the forming and storage parameters than to that involving dipoles. The observed dependence of the peak temperature as well as the activation energy for various peaks on polarizing temperature and time is indicative of a continuous distribution of relaxations.

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The polarization mechanism due to corona discharge has been investigated in Kapton polyimide film by applying thermally stimulated discharge current technique. Three peaks were observed in TSC spectra. These peaks are attributed to the shallow and deep trap levels present in Kapton. Heat treatment causes a decrease in the peak current which may be due to the reduction in the number of traps. Iodine doping increases the peak current nearly ten times which may be due to the increase in number of carriers as a result of diffusion of I, ions in the polymer matrix. Studies of surface potential decay show that photo decay rate is much higher than dark decay rate. Heat treatment and iodine doping increase the dark decay rate. Charakteristika des Zerfalls des Oberflachenpotentials und TSDC-Messungen an durch corona-Entladung aufgeladenen Poly imidfilmenDer Mechanismus der Polarisierung durch Corona-Entladung wurde an Polyimidfilmen (Kapton) durch TSDC-Messungen untersucht. I n den TSC-Spektren wurden drei Peaks beobachtet, die den flachen und tiefen Haf tstellen (Traps) im Kapton zugeordnet werden. Warmebehandlung hat eine Abnahme der Peakstrome zur Folge, was auf die Verringerung der Anzahl der Haftstellen zuriickgefuhrt wird. Bei Dotierung mit Iod wachst der Peakstrom auf nahezu den zehnfachen Wert an. Dies wird durch die Zunahme der Anzahl der Ladungstrager infolge der Diffusion von I,-Ionen in die Polymermatrix erklart. Untersuchungen zum Zerfall des Oberflachenpotentials zcigen, daB der Zerfall im Licht vie1 hoher als im Dunkeln ist. Nach Warmebehandlung und Dotierung mit Iod nimmt die Zerfallsgeschwindigkeit im Dunkeln zu. Xapanmepucmunu pacnaaa nosepxuocmuoeo nomenyuaaa u TCPT-uaaepenm na 3 a p~m e n i m x noponnmu p a a p d o & nofiuu&uawcx nfiennaxMeXaHM3M nOJIRpH3a~HEI KOpOHHbIM paBpI?AOM MCCJIeAOBClH H a IIOJIMMMMAHbIX llJIeHKaX (KalITOH) C JIOMOLUbH) T c P T -~3~e p e~w t .06HapyHteHbI TPM nMKa B TCT-cnempax, OTHeCeHHbIe K IIJIOCKkiM EI FJIy60KEIM JIOByLUKaM B KaIITOHe. TepMHYeCKaR 0 6 p a 6 0~~a IIpHBOgHT K CHHHW?HEIH) IIEIKOBbIX TOKOB, YTO MOmeT 6bITb 06yCXOBJIeHO YMeHb-lIIeHMeM KOJIEIYeCTBa JIOBymeK. n p l i AOTHPOBaHElH BOAOM IIMKOBbIfi TOK BO3paCTaeT IIOYTM H a OAHH n0pRAOK. 3 T O MOmeT 6bITb 06' 61ICHeHO yBeJlEIYt?HHeM KOJIEIYeCTBa HOCliTeJIefi 3apRAa BCJIeACTBHe AM@@Y3EIH 12-MOHOB B IlOJIMMepHyH) MaTpMqy. HccnegoBaHm no pacnagy noBepxHocTHoro n o~e~q~a n a noKaamamT, YTO p a c n a H a cBeTe 6onee HHTeH-CMBeH W?M B TeMHOTe. nOCJIe TepMMYeCKO&t 0 6 p a 6 o~~~ ki gOTHpOBaHHR fiOAOM CKOpOCTb paCIIaAa B TeMHOTe YBenH-9HBaeTCR.

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An attempt has been made to distinguish space charge and dipolar polarisation in Kapton-H polymer thin film. The conclusions drawn on the basis of thermally stimulated discharge current (TSDC) investigations are further confirmed by thermally stimulated polarisation current (TSPC) studies. The other techniques adopted for a decisive discrimination include the electrode-metal effect on the TSDC spectrum and van Turnhout's method, based on charging current measurement under equal fields of reverse polarity applied successively. In addition, simultaneous measurement of TSPC and thermally stimulated conductivity (TSC) have been carried out according to McKeever's procedure. The results corroborate the above inferences.