Electrically tunable sign of capacitance in planar W-doped vanadium dioxide micro-switches

Mohammed Soltani; Mohamed Chaker; Joelle Margot

doi:10.1088/1468-6996/12/4/045002

Electrically tunable sign of capacitance in planar W-doped vanadium dioxide micro-switches

Sci Technol Adv Mater. 2011 Jul 7;12(4):045002. doi: 10.1088/1468-6996/12/4/045002. eCollection 2011 Aug.

Authors

Mohammed Soltani¹, Mohamed Chaker¹, Joelle Margot²

Affiliations

¹ INRS-Énergie, Matériaux et Télécommunications, 1650 Lionel Boulet, Varennes, QC, J3X 1S2, Canada.
² Département de Physique, Université de Montréal, Montréal, QC, H3C 3J7, Canada.

Abstract

Negative capacitance (NC) in a planar W-doped VO₂ micro-switch was observed at room temperature in the low-frequency range 1 kHz-10 MHz. The capacitance changed from positive to negative values as the W-doped VO₂ active layer switched from semiconducting to metallic state under applied voltage. In addition, a capacitance-voltage hysteresis was observed as the applied voltage was cycled from -35 to 35 V. These observations suggest that NC results from the increase of the electrically induced conductivity in the active layer. This NC phenomenon could be exploited in advanced multifunctional devices including ultrafast switches, field-effect transistors and memcapacitive systems.

Keywords: negative capacitance; phase transition; switching; thermochromic; vanadium dioxide.