Field-induced anomalous changes in Cr/a-Si : H/V thin film structures

Citation
J. Hu et al., Field-induced anomalous changes in Cr/a-Si : H/V thin film structures, THIN SOL FI, 396(1-2), 2001, pp. 240-249
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
THIN SOLID FILMS
ISSN journal
0040-6090 → ACNP
Volume
396
Issue
1-2
Year of publication
2001
Pages
240 - 249
Database
ISI
SICI code
0040-6090(20010921)396:1-2<240:FACIC:>2.0.ZU;2-W
Abstract
Experimental results on the electronic properties of conditioned Cr/hydroge nated amorphous silicon (a-Si:H)/V thin film devices are presented. The dev ices under test were electro-formed, and had resistances in the range from several hundred Ohms to several kiloOhms. The current of conditioned device s varied non-linearly with bias at low voltages, but exhibited 'jumps' at a threshold voltage (V-th) (typically 2-3 V), leading to a resistance change of one to three orders of magnitude. Above V-th the current increased almo st linearly with bias, and the carrier transport changed from a semiconduct ing behaviour to a more conducting (metallic) state. This was confirmed by a.c. characteristics of the conditioned devices, which showed a transition from a capacitive to an inductive behaviour around V-th. The threshold volt age V-th, was found to decrease with increasing temperature and disappeared at 340-350 K, but recovered when the temperature was reduced. The transiti on at V-th has been analysed in terms of an electrothermal mechanism. The c alculated turnover temperature is approximately 346 K, close to that for th e disappearance of Vh. We suggest that the observed transition could involv e vanadium oxides such as VO2. The phase transition could also facilitate t he underlying 'quantisation' effect. (C) 2001 Elsevier Science B.V. All rig hts reserved.