Organo and amino phosphonium cation derived ferro and piezoelectric materials and their utility in mechanical energy harvesting applications

Abstract

Multifunctional materials displaying ferroelectricity are very attractive for their utility in high technique applications in the areas of energy and electronics Traditionally inorganic ceramic oxides are employed as commercial ferroelectric materials However they require high temperature syntheses high voltage poling and the presence of heavy and toxic elements limits their application in certain fields of application In this regard ferroelectrics consisting of organic and hybrid organic inorganic materials have been extensively investigated because of their easy synthesis light weight high flexibility and high polarization values This presentation will highlight the design and synthesis of small molecules based on organic and organic inorganic hybrid ferroelectric materials supported by organo and aminophosphonium salts and their utility in mechanical energy harvesting applications By employing the flexible phosphorus centred scaffolds containing heteroleptic organo and amino substituents we synthesized organic and hybrid organic inorganic phosphonium salts in non centrosymmetric assemblies The substituents around the cationic phosphorus centre were varied from alkyl to aryl to amino groups in the presence of diverse anions such as Cl 8210 Br 8210 I 8210 PF6 8210 BF4 8210 ClO4 8210 IO4 8210 M CN 6 3 8210 M Fe Co and Ni NCS 6 4 8210 ions Ferroelectric measurement on single crystals of several of these materials showed high remnant polarization values Since the piezoelectric coefficient is directly proportional to the electric polarization a number of the materials of these series with high remnant polarization were utilized to prepare composite piezoelectric device materials with a non piezoelectric polymer such as polydimethylsiloxane and thermoplastic polyurethane These composite devices show excellent output electromechanical responses such as output voltage output current current and power density values under various impact forces All these results demonstrate a promising development for the use