Pyroelectric response and dielectric behaviour of corona charged and dc field polarized PVDF films

Dielectric relaxation and pyroelectric response of PVDF films poled in low dc field and corona charged was studied. Pyroelectric coefficient p of corona charged PVDF diaphragm is weakly dependent on light modulation frequency f from a dozen of Hz to a few kHz. The same is found for diaphragms made of film poled in dc field when the side being positive is illuminated, however, a low-frequency anomaly in p(f) is observed when the side being grounded during poling is illuminated. Poling-induced compensating charges, piled up at the crystalline phase of a semicrystalline polymer, influence the /spl beta/-relaxation in MHz frequency range.