Field-induced anomalous changes in Cr/a-Si:H/V thin film structures
Experimental results on the electronic properties of conditioned Cr/hydrogenated amorphous silicon (a-Si:H)/V thin film devices are presented. The devices under test were electro-formed, and had resistances in the range from several hundred Ohms to several kiloOhms. The current of conditioned device...
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Published in | Thin solid films Vol. 396; no. 1; pp. 242 - 251 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
21.09.2001
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Subjects | |
Online Access | Get full text |
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Summary: | Experimental results on the electronic properties of conditioned Cr/hydrogenated amorphous silicon (a-Si:H)/V thin film devices are presented. The devices under test were electro-formed, and had resistances in the range from several hundred Ohms to several kiloOhms. The current of conditioned devices 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 almost linearly with bias, and the carrier transport changed from a semiconducting 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 voltage
V
th, was found to decrease with increasing temperature and disappeared at 340–350 K, but recovered when the temperature was reduced. The transition at
V
th has been analysed in terms of an electrothermal mechanism. The calculated turnover temperature is approximately 346 K, close to that for the disappearance of
V
th. We suggest that the observed transition could involve vanadium oxides such as VO
2. The phase transition could also facilitate the underlying ‘quantisation’ effect. |
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ISSN: | 0040-6090 1879-2731 |
DOI: | 10.1016/S0040-6090(01)01188-9 |