microwave imaging of electronic inhomogeneity in phase ... · center for probing the nanoscale,...
TRANSCRIPT
Center Highlight
Microwave Imaging of Electronic Inhomogeneity in Phase-change In2Se3 Nanoribbons
PI: Zhi-Xun Shen Keji Lai, Hailin Peng, Worasom Kundhikanjana, David T. Schoen, Chong Xie, Stefan Meister, Yi Cui, Michael A. Kelly
NSF NSEC Grant PHY-0425897 Center for Probing the Nanoscale, Stanford University
Direct visualization of nanoscale electronic properties provides valuable information for fundamental physics, material sciences, and electronic device applications. Using a microwave impedance microscope (MIM), we report the observation of electronic inhomogeneity, as shown below, in phase-change In2Se3 nanoribbon devices. Although the SEM and AFM images display a flat surface, the microwave images show strong non-uniform local conductivity of this In2Se3 nanoribbon contacted by four In/Au electrodes. The bright regions (red dots) in the capacitive channel (MIM-C) are highly conductive due to the superlattice structures. The bright areas (green dots) in the loss channel (MIM-R) correspond to intermediate conductivity. The amorphous and highly resistive regions (blue dots) appear dark in both channels. The MIM response is also consistent with the two-terminal DC resistance.
REFERENCE: K. Lai, H. Peng, W. Kundhikanjana, D. Schoen, C. Xie, S. Meister, Y. Cui, M.A. Kelly and ZX Shen Nano Lett. 9, 1265 (2009)
SEM
AFM
100MΩ
200M
Ω
2MΩ
650mV 140mV
MIM-C MIM-R
2µm 2µm
In/Au