2017/10/10 by Xiaohui Liu, Evgeny Y. Tsymbal, Karin M. Rabe
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Chemistry #Condensed matter physics #Conductance #Doping #Electronic and Structural Properties of Oxides #Ferroelectric and Negative Capacitance Devices #Ferroelectric and Piezoelectric Materials #Ferroelectricity #Field-effect transistor #Heterojunction #Materials science #Modulation (music) #Optoelectronics #Physical chemistry #Physics #Polarization (electrochemistry) #Quantum mechanics #Transistor #Voltage #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.97.094107
published as Phys. Rev. B 97, 094107 (2018) · 9 pages, 8 figures
arxiv created 2017/10/10 · openalex publication_date 2018/03/20 · arxiv updated 2018/03/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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\ensuremath-SrTiO3 (electron-doped SrTiO3) and PbTiO3/n\ensuremath-SrTiO3 as prototypical systems. It is shown that the modulation doping is substantial in both cases, and that the electrostatic model developed in previous work can be used to predict electron transfer. This model can thus be used to suggest additional materials heterostructures for the design of active FeFETs.