Study On Electrocaloric Effect Of PZT-Based Ferroelectric And Its Application In Friction Nanogenerator

Lead zirconate titanate-based ferroelectric thin films have been widely used in sensors,energy storage capacitors,solid-state refrigeration and triboelectric nanogenerators(TENG)due to its excellent ferroelectric,piezoelectric and electrocaloric effect(EC)properties.In this paper,Pb(Zr_0.3Ti_0.7)O₃-Mn ferroelectric thin film deposited on different substrates by using sol-gel method.The ferroelectric properties and electrocaloric effect on Pt(111)/TiOx/SiO₂/Si(100),p-Ga N(n=4×10¹⁷),La Ni O₃/Si and n-Si(100)substrates were systematic studied in detail.At the same time,a Pb(Zr_0.3Ti_0.7)O₃gel with the same concentration was configured and calcined into nano-powders,and then the prepared samples were composited with PVDF organic ferroelectric polymer materials,and triboelectric nanogenerator was constructed by an electrostatic spinning method.The results are as follows:(1)Mn-doped Pb(Zr_0.3Ti_0.7)O₃(PZT)ferroelectric material was deposited on Pt(111)/TiOx/SiO₂/Si(100)substrate layer by layer through gel-sol method,crystallization and annealing PZT-Mn ferroelectric thin film was grown with different routes.It is concluded that the film grown on this substrate has a larger electrical card effect at?313 K,namely(35)T_max?44.5 K and(35)S_max?-42.8JK^-1kg^-1.The thin film deposited on the p-Ga N(n=4×10¹⁷)substrate with the same method obtains a pure wide temperature range negative electrocaloric effect.Where(35)T_max?-23.5 K,(35)S_max?16.3JK^-1kg^-1,the temperature range is?150 K.Under the sprouting of the p-Ga N-substrate,the electric-field-induced structural-phase-transition(nano-scaled tetragonal phase to rhombohedral phase)plays a key role on the recorded pure negative EC effect with a super-broad operational temperature range.(2)Triboelectric nanogenerators were fabricated by PVDF/PZT composite films using electrospinning.The output performance increases with the increase of the doping ratio of PZT nano-powders,and the doping ratio of PZT2%wt-PVDF8%wt achieves V_OC?400 V,and the power density is 7.6 W m^-2.The phenomenons are ascribed to other crystalline phases of PVDF were transformed into more?-phases by PZT pinning during electrospinning and the use of the ferroelectric-triboelectric synergistic effect can increase the output of triboelectric nano-powders.Consequently,the friction nano generator can light up>350 LED lights at the same time.