Negative differential resistors from carbon-based cryogels incorporating graphene oxide into a ferroelectric polymer matrix

Abstract

Electronic components with negative differential resistance (NDR) are essential in power electronics to build Gunn diodes, varactors, parametric amplifiers and switching circuits. However, their implementation through silicon-based electronics is costly and demands complex circuitry and components. Here, we introduce for the first time a class of hybrid carbon-based and organic aerogels, prepared at liquid nitrogen temperature (77 K) by a simple and scalable freeze-drying method. These cryogels exhibit NDR. In these cryogels, the carbonaceous phase is represented by d-glucose-graphene oxide nanocomposites while the organic phase is represented by polyvinylidene difluoride (PVDF), a ferroelectric polymer. NDR in our samples is assigned to the local electric field effects of PVDF on the charge carriers of more electrically conducting graphene oxide and d-glucose. Through an operando study via scanning near-field optical microscopy, we also show that low thermal expansion and low thermal conductivity are essential to prevent undesired effects in our devices through parasitic capacitance's discharge.