Forming-free bipolar resistive switching in nonstoichiometric ceria films.
The mechanism of forming-free bipolar resistive switching in a Zr/CeOx/Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrOy layer at the Zr/CeOx interface. X-ray diffraction studies of CeOx films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeOx film and in the nonstoichiometric ZrOy interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).
Muhammad
M
Ismail
Chun-Yang
CY
Huang
Debashis
D
Panda
Chung-Jung
CJ
Hung
Tsung-Ling
TL
Tsai
Jheng-Hong
JH
Jieng
Chun-An
CA
Lin
Umesh
U
Chand
Anwar Manzoor
AM
Rana
Ejaz
E
Ahmed
Ijaz
I
Talib
Muhammad Younus
MY
Nadeem
Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan. tseng@cc.nctu.edu.tw.
Tseung-Yuen
TY
Tseng