A Graphene-Edge Ferroelectric Molecular Switch

Abstract

We show that polar molecules (water, ammonia, and nitrogen dioxide) adsorbed solely at the exposed edges of an encapsulated graphene sheet exhibit ferroelectricity, collectively orienting and switching reproducibly between two available states in response to an external electric field. This ferroelectric molecular switching introduces drastic modifications to the graphene bulk conductivity and produces a large and ambipolar charge bistability in micrometer-size graphene devices. This system comprises an experimental realization of envisioned memory capacitive ("memcapacitive") devices whose capacitance is a function of their charging history, here conceived via confined and correlated polar molecules at the one-dimensional edge of a two-dimensional crystal.

Single-particle and collective excitations of polar water molecules confined in nano-pores within a cordierite crystal lattice

“…21–26 It is worth noting that ordered water dipoles can also find applications in nanoelectronic devices. 27–31 The existence of various types of dipolar orderings of H 2 O molecules has been predicted theoretically or demonstrated by computer simulations; however, until recently, no robust experimental observation under ambient conditions has been reported. 32–42 However, in a very recent study 43 we were able to demonstrate that such a state indeed can be formed when single water molecules are confined in cages existing within the crystalline lattice of cordierite, a beryl-related compound.…”

QuantumATK: an integrated platform of electronic and atomic-scale modelling tools

“…2 Furthermore, QuantumATK provides a highly flexible and efficient framework for coupling advanced electrostatic setups with state-of-the-art transport simulations including electron-phonon coupling and light-matter interaction. This has enabled predictions of gate-induced phonon scattering in graphene gate stacks, 35 atomistic description of ferroelectricity driven by edge-absorbed polar molecules in gated graphene, 36 and new 2D material science such as prediction of the room-temperature photocurrent in emerging layered Janus materials with a large dipole across the plane. 37 The flexibility of the QuantumATK framework supports the imagination of researchers, and at the same time enables solutions to both real-world and cutting-edge semiconductor device and material science problems.…”

Dielectric ordering of water molecules arranged in a dipolar lattice

“…Various types of dipolar orderings and other exciting properties are predicted based on theoretical analyses or computer simulations of water molecules in nanometer-thick layers on substrates or at the interface [9][10][11][12][13] , between two graphene layers [14][15][16][17] , for H 2 O chains within carbon nanotubes [18][19][20][21][22][23] , for networks of H 2 O molecules in nanovoids, e.g., in fullerenes [24][25][26] or within protein hydration shells 27 . Besides fundamental aspects, the interest in such systems is fueled by the perspective that ordered water dipoles can find practical applications in nanoelectronic devices [28][29][30][31][32][33] . It turned out, however, that it is not so trivial to experimentally verify the predictions made by theory and modeling.…”