Symmetrical negative differential resistance behavior of a resistive switching device.
With a thin insulator sandwiched between two electrodes, the negative differential resistance (NDR) behavior has been frequently reported for its potential device applications. Here we report the experimental observation of a symmetric NDR characteristic in a resistive switching device based on TiO(2). We propose a charge storage mechanism for the NDR effect, with oxygen molecular ions working as the active source, in a thin insulating layer. Current-voltage measurements demonstrated a highly reproducible state at about 0.65 eV, and the photoelectron spectroscopy measurements showed that it complies well with the Ti3d band gap state. Our first-principle calculations confirm that charge storage and release arise from trapping and detrapping of oxygen molecular ions at the defect sites. The results and mechanism demonstrated here in a thin layer could be extended to other systems approaching molecular dimensions for device applications.
Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore. yuanmin@nus.edu.sg
Yuanmin
Y
Du
Hui
H
Pan
Shijie
S
Wang
Tom
T
Wu
Yuan Ping
YP
Feng
Jisheng
J
Pan
Andrew Thye Shen
AT
Wee