Physics of organic ferroelectric field-effect transistors

Most of the envisaged applications of organic electronics require a nonvolatile memory that can be programmed, erased, and read electrically. Ferroelectric field-effect transistors (FeFET) are especially suitable due to the nondestructive read-out and low power consumption. Here, an analytical model is presented that describes the charge transport in organic FeFETs. The model combines an empirical expression for the ferroelectric polarization with a density dependent hopping charge transport in organic semiconductors. Transfer curves can be calculated with parameters that are directly linked to the physical properties of both the comprising ferroelectric and semiconductor materials. A unipolar FeFET switches between a polarized and depolarized state, and an ambipolar FeFET switches between two stable polarized states. A good agreement between experimental and calculated current is obtained. The method is generic; any other analytical model for the polarization and charge transport can be easily implemented and can be used to identify the origin of the different transconductances reported in the literature.