Piezoelectric properties of CH3NH3PbI3 perovskite thin films and their applications in piezoelectric generators

CH3NH3PbI3 (MAPbI(3)) perovskite thin films were applied to fluorine-doped SnO2 (FTO)/glass and Au/Ti/polyethylene terephthalate (PET) substrates via a two-step process, which involved depositing a CH3NH3I (MAI) solution onto PbI2 films via spin-coating followed by crystallization at temperatures of 100 degrees C. The 500 nm-thick crystallized MAPbI3 perovskite thin films showed a Curie temperature of similar to 328 K, a dielectric permittivity of similar to 52, a dielectric loss of similar to 0.02 at 1MHz, and a low leakage current density of similar to 10(7) A cm(2) at +/- 3V. The polarization-electric field (P-E) hysteresis loop and piezoresponse force microscopy (PFM) results showed that the films had well-developed ferroelectric properties and switchable polarization. Poling at an electrical field of 80 kV cm(1) enhanced the power density of the generator. The values for output voltage and current density of the poled films reached 2.7 V and 140 nA cm(2), respectively, which were 2.7-fold higher than those of the non-poled samples.