Giant Electroresistive Ferroelectric Diode on 2DEG.

Kim, Shin-Ik; Keun Kim, Seong; Choi, Ji-Won; Baek, Seung-Hyub; Jin Gwon, Hyo; Yoon, Seok-Jin; Kwon, Beomjin; Kim, Jin-Sang; Kim, Dai-Hong; Hong, Seong-Hyeon; Jung Chang, Hye; Kang, Chong-Yun; Bark, Chung-Wung

Manipulation of electrons in a solid through transmitting, storing, and switching is the fundamental basis for the microelectronic devices. Recently, the electroresistance effect in the ferroelectric capacitors has provided a novel way to modulate the electron transport by polarization reversal. Here, we demonstrate a giant electroresistive ferroelectric diode integrating a ferroelectric capacitor into two-dimensional electron gas (2DEG) at oxide interface. As a model system, we fabricate an epitaxial Au/Pb(Zr0.2Ti0.8)O3/LaAlO3/SrTiO3 heterostructure, where 2DEG is formed at LaAlO3/SrTiO3 interface. This device functions as a two-terminal, non-volatile memory of 1 diode-1 resistor with a large I /I− ratio (>108 at ±6 V) and Ion/Ioff ratio (>107). This is attributed to not only Schottky barrier modulation at metal/ferroelectric interface by polarization reversal but also the field-effect metal-insulator transition of 2DEG. Moreover, using this heterostructure, we can demonstrate a memristive behavior for an artificial synapse memory, where the resistance can be continuously tuned by partial polarization switching, and the electrons are only unidirectionally transmitted. Beyond non-volatile memory and logic devices, our results will provide new opportunities to emerging electronic devices such as multifunctional nanoelectronics and neuromorphic electronics.

FERROELECTRIC devices; DIODES; TWO-dimensional electron gas; POLARIZATION (Electricity); FERROELECTRIC crystals

Scientific Reports, 2015, p10548

2045-2322

Academic Journal

10.1038/srep10548