Abstract
Plasmonic and metamaterial based nano/micro-structured materials enable spectrally selective resonant absorption, where the resonant bandwidth and absorption intensity can be engineered by controlling the size and geometry of nanostructures. Here, we demonstrate a simple, lithography-free approach for obtaining a resonant and dynamically tunable broadband absorber based on vanadium dioxide (VO2) phase transition. Using planar layered thin film structures, where top layer is chosen to be an ultrathin (20 nm) VO2 film, we demonstrate broadband IR light absorption tuning (from ∼90% to ∼30% in measured absorption) over the entire mid-wavelength infrared spectrum. Our numerical and experimental results indicate that the bandwidth of the absorption bands can be controlled by changing the dielectric spacer layer thickness. Broadband tunable absorbers can find applications in absorption filters, thermal emitters, thermophotovoltaics and sensing.
Original language | English (US) |
---|---|
Article number | 13384 |
Journal | Scientific reports |
Volume | 5 |
DOIs | |
State | Published - Aug 21 2015 |
Funding
This research was supported by the Materials Research Science and Engineering Center (NSF-MRSEC) (DMR-1121262) of Northwestern University. K.A. acknowledges financial support from the McCormick School of Engineering and Applied Sciences at Northwestern University and partial support from the AFOSR under Award No. FA9550-12-1-0280 and the Institute for Sustainability and Energy at Northwestern (ISEN) through ISEN Equipment and Booster Awards. The material preparation work at Berkeley was supported by a NSF CAREER Award under Grant DMR-1055938. H.K. was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) through a postdoctoral research fellowship program. This research made use of the NUANCE Center at Northwestern University, which is supported by NSF-NSEC, NSF-MRSEC, Keck Foundation, and the State of Illinois and the NUFAB cleanroom facility at Northwestern University.
ASJC Scopus subject areas
- General