A new organic-inorganic hybrid perovskite ferroelectric [ClCHCHN(CH)][PbBr] and Its PVDF matrix-assisted highly-oriented flexible ferroelectric films

A new organic-inorganic hybrid perovskite ferroelectric, [ClCH 2 CH 2 N(CH 3 ) 3 ][PbBr 3 ] ( CEPbBr ) was obtained by the reaction of (2-chloroethyl) trimethylammonium chloride [ClCH 2 CH 2 N(CH 3 ) 3 ] + Cl − with lead( ii ) bromide in a HBr aqueous solution. CEPbBr could undergo a reversible phase transition at 315/300 K with the space group change from Cc to Pna 2 1 and exhibit the dielectric, SHG, and ferroelectric triple transitions between high and low states as a response to a temperature stimulus. The experimental spontaneous polarization ( P s ) before and after phase transition for the single crystal sample is 6.20 μC cm −2 and 0.28 μC cm −2 , respectively. In order to solve the problem of randomly distributed dipole orientation of powder-pressed pellet, highly-oriented flexible ferroelectric films were obtained by the method of β-phase dominated PVDF matrix-assisted in situ growth of CEPbBr particles. The protocol of inducing a preferred orientation by a polymer matrix may be key to developing highly-oriented flexible ferroelectric thin films for electronic applications. A hybrid perovskite with dielectric, SHG, and ferroelectric triple transitions was tailored into highly-oriented films using PVDF matrix-assisted in situ growth.