Pyroelectric homogeneity of corona-charged P(VDF/TrFE) films

Temperature variation of pyroelectric response of P(VDF/TrFE) (75/25)-14 mu m was studied in light modulation frequency range 1 Hz to 50 kHz at various excitation-response configurations. Since the dielectric behaviour of the film is involved in the dynamic pyroelectric characteristics important in the applications we measured also dielectric dispersion and thermally stimulated current. Pyroelectric coefficient p of the copolymer samples in form of diaphragm fixed on its perimeter does not depend on whether the positively, or negatively charged surface of the film is illuminated. Moreover, the p value is linearly dependent on the light modulation frequency fin the range 1-50 Hz and is frequency independent in the range 50 Hz - 1 kHz. The pyroelectric coefficient is constant in the temperature range 10 degrees C - 100 degrees C and thermal annealing causes a small decrease in the p-value.