TY  - JOUR
AU  - Shang, Dashan
AU  - Li, Peining
AU  - Wang, Tao
AU  - Carria, Egidio
AU  - Sun, Jirong
AU  - Shen, Baogen
AU  - Taubner, Thomas
AU  - Valov, Ilia
AU  - Waser, Rainer
AU  - Wuttig, Matthias
TI  - Understanding the conductive channel evolution in Na:WO $_{3−x}$ -based planar devices
JO  - Nanoscale
VL  - 7
IS  - 14
SN  - 2040-3372
CY  - Cambridge
PB  - RSC Publ.
M1  - FZJ-2015-03773
SP  - 6023 - 6030
PY  - 2015
AB  - An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO3−x) films on a soda-lime glass substrate, from which Na+ diffuses into the WO3−x films during the deposition. The entire process of Na+ migration driven by an alternating electric field is visualized in the Na-doped WO3−x films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na+ mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000351934700015
DO  - DOI:10.1039/C4NR07545E
UR  - https://juser.fz-juelich.de/record/201478
ER  -