In:
Advanced Electronic Materials, Wiley, Vol. 1, No. 7 ( 2015-07)
Abstract:
Electrolyte gating on correlated VO 2 thin films enables electrical control of the “bulk” electronic and structural phases over the electrostatic screening length. Although this unique functionality potentially provides novel electronic and optoelectronic device applications, there are intense discussions on the mechanism of the device operation both from electrostatic and electrochemical viewpoints. Here it is shown that the reversibility of the device operation strongly depends on substrates, suggesting that a governing mechanism might differ depending on substrates. Electrolyte gating on VO 2 films grown on lattice‐matched TiO 2 substrates shows reversible gating effects, whereas that on hexagonal Al 2 O 3 substrates become irreversible, although in both cases metallic states can be induced electrically. X‐ray absorption spectroscopy measurements on irreversibly gated VO 2 /Al 2 O 3 reveal permanent reduction of the valence state of vanadium upon gate‐induced metallization, presumably originating from irreversible electrochemical doping under the presence of the extremely large electric field created at an electrolyte/VO 2 interface. Our findings suggest essential importance of the film quality for future fundamental researches as well as for practical device applications based on electrolyte‐gated devices.
Type of Medium:
Online Resource
ISSN:
2199-160X
,
2199-160X
DOI:
10.1002/aelm.201500093
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2810904-1
