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Title: Antenna-coupled microbolometer based on VO 2 's non-linear properties across the metal–insulator transition region
This paper presents an antenna-coupled non-linear vanadium dioxide (VO 2 ) microbolometer operating in the non-linear metal–insulator transition (MIT) region with an ultra-high responsivity of 6.55 × 10 4 V/W. Sputtered VO 2 films used in this device exhibit 10 4 times change in resistivity between the dielectric and conductive states. The VO 2 microbolometer is coupled to a wideband dipole antenna operating at 31–55 GHz and a coplanar waveguide for probed measurement. To enhance the sensitivity, the sensor is suspended in air by micro-electro-mechanical systems process. The large thermal coefficient of resistance of VO 2 is utilized by DC biasing the device in the MIT region. Measurements for the fabricated sensor were performed, and a high responsivity was demonstrated, owing to non-linear conductivity change in the transition region. The measured sensitivity is >10 2 times higher than the state-of-the-art sensors. In addition, the concept of utilizing the proposed VO 2 sensor in a mmWave imager was demonstrated by the radiation pattern measurement of a 4 × 4 (16 elements) antenna-coupled VO 2 sensor array. The results presented in this work reveal the initial step to employ VO 2 's MIT for a hyper-sensitive sensor in future mmWave sensing and imaging applications.  more » « less
Award ID(s):
2149886
PAR ID:
10383391
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Applied Physics Letters
Volume:
121
Issue:
20
ISSN:
0003-6951
Page Range / eLocation ID:
201901
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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