Polarization-controlled modulation doping of a ferroelectric from first principles

Abstract

In a ferroelectric field effect transistor (FeFET), it is generally assumed that the ferroelectric gate plays a purely electrostatic role. Recently it has been shown that in some cases, which could be called 'active FeFETs', electronic states in the ferroelectric contribute to the device conductance as the result of a modulation doping effect in which carriers are transferred from the channel into the ferroelectric layers near the interface. Here we report first-principles calculations and model analysis to elucidate the various aspects of this mechanism and to provide guidance in materials choices and interface termination for optimizing the on-off ratio, using BaTiO3/n-SrTiO3 and PbTiO3/n-SrTiO3 as prototypical systems. It is shown that the modulation doping is substantial in both cases, and that extension of an electrostatic model developed in previous work provides a good description of the transferred charge distribution. This model can be used to suggest additional materials heterostructures for the design of active FeFETs.

9 pages, 8 figures

References in corpus (7)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Understanding and controlling the work function of perovskite oxides using Density Functional Theory
• Ferroelectric Instability under Screened Coulomb Interactions
• Band alignment and charge transfer in complex oxide interfaces
• Termination Control of the Interface Dipole in La${}_{0.7}$Sr${}_{0.3}$MnO${}_3$/Nb:SrTiO${}_3$ (001) Schottky Junctions
• First-principles study of the mobility of SrTiO${}_3$
• Evolution of the band alignment at polar oxide interfaces

Cited by in corpus (3)

• Fabrication of high-temperature quasi-two-dimensional superconductors at the interface of a ferroelectric Ba${}_{0.8}$Sr${}_{0.2}$TiO${}_3$ film and an insulating parent compound of La${}_2$CuO${}_4$
• Pressure-induced enhancement of non-polar to polar transition temperature in metallic LiOsO${}_3$
• Contrasting Ferromagnetism in Pyrite FeS${}_2$ Induced by Chemical Doping versus Electrostatic Gating