A Room-Temperature Ferroelectric Resonant Tunneling Diode.

Ma, Zhijun; Zhang, Qi; Tao, Lingling; Wang, Yihao; Sando, Daniel; Zhou, Jinling; Guo, Yizhong; Lord, Michael et al. · Adv Mater · 2022

basic_science · Level V

Where this comes from

Abstract

Resonant tunneling is a quantum-mechanical effect in which electron transport is controlled by the discrete energy levels within a quantum-well (QW) structure. A ferroelectric resonant tunneling diode (RTD) exploits the switchable electric polarization state of the QW barrier to tune the device resistance. Here, the discovery of robust room-temperature ferroelectric-modulated resonant tunneling and negative differential resistance (NDR) behaviors in all-perovskite-oxide BaTiO<sub>3</sub> /SrRuO<sub>3</sub> /BaTiO<sub>3</sub> QW structures is reported. The resonant current amplitude and voltage are tunable by the switchable polarization of the BaTiO<sub>3</sub> ferroelectric with the NDR ratio modulated by ≈3 orders of magnitude and an OFF/ON resistance ratio exceeding a factor of 2 × 10<sup>4</sup> . The observed NDR effect is explained an energy bandgap between Ru-t<sub>2g</sub> and Ru-e<sub>g</sub> orbitals driven by electron-electron correlations, as follows from density functional theory calculations. This study paves the way for ferroelectric-based quantum-tunneling devices in future oxide electronics.