Comparative study of pyroelectric response of PZT-film/Si,   PZT-film/Por-Si/Si and PVDF-film/Si structures
  The comparative investigation of pyroelectric response modulation frequency dependences of structures of "polar active film-Si substrate" type based on PZT and PVDF and of structures of "polar active film - buffer layer - Si substrate" type based on PZT and porous silicon (por-Si) has been carried out. By photopyroelectric modulation method the thermowave pyroelectric "under-surface" probing was performed and amplitude-to-frequency and phase-to-frequency dependences of pyroelectric response of investigated systems in the voltage and current modes were obtained. By performing the analysis of obtained dependences the thermal diffusivity values of investigated PZT and PVDF films, and also por-Si interlayer were estimated. The results of theoretical consideration of the structures under investigation are in a good agreement with the experimental data. The problem of thermal decoupling and self-decoupling from position of chain "frequency-thickness-material" and question of complete and incomplete thermal linkage are briefly discussed. The obtained results show that a por-Si layer is a suitable material for effective thermal decoupling of polar active film and heat removing Si-substrate which realized in significant increase of pyroelectric response value and approach it to that of characteristic for a free sensitive element. 
S. Bravina, N. Morozovsky, E.A. Eliseev, E. Cattan, D. Remiens and A.   Grosman