Active modulation of the optical absorption coefficient of sputtered VO2 nanostructure by external temperature stimuli

Autor: Malik Maaza, J. B. Kana Kana, Balla D. Ngom
Rok vydání: 2013
Předmět:
Zdroj: Journal of Optics. 43:28-33
ISSN: 0974-6900
0972-8821
Popis: The development of materials that respond to a stimulus and whose mechanisms are based on phase transitions have enabled progress towards the engineering of the tunable optoelectronic devices, ac- tive plasmonic devices and tunable infrared active metamaterials. Vanadium dioxide (VO2) is a promising candidate that exhibits a sharp metal-insulator phase transition at ultrafast timescales, which is accompanied by a significant and reversible variation of the refrac- tive index and optical absorption coefficient. Here we report on the modulation of the absorption coefficient of sputtered VO2 nanostructure via the external tem- perature stimuli. The absorption coefficient at low and high photon energies experiences an abrupt change and show sharp hysteresis near the critical temperature of 70 °C. Temperature dependence of the insulating VO2 optical band-gap energy shows a significant decrease from 0.74 to 0.41 eV with increasing the external temperature stimuli from 35 to 65 °C. Conductive atomic force microscopy reveals an island-like growth with well-defined columnar structure and also coexis- tence of insulating and metallic domains.
Databáze: OpenAIRE
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