biostudies-literatureBoyce AMAmerican Society for Engineering EducationArmy Research OfficeAir Force Office of Scientific ResearchOffice of Naval Research3525-3531https://www.ebi.ac.uk/biostudies/studies/S-EPMC9101075biostudies-literatureUnknown22(9)Actively tunable optical materials integrated with engineered subwavelength structures could enable novel optoelectronic devices, including reconfigurable light sources and tunable on-chip spectral filters. The phase-change material vanadium dioxide (VO₂) provides a promising solid-state solution for dynamic tuning; however, previous demonstrations have been limited to thicker and often rough VO₂ films or require a lattice-matched substrate for growth. Here, sub-10-nm-thick VO₂ films are realized by atomic layer deposition (ALD) and integrated with plasmonic nanogap cavities to demonstrate tunable, spectrally selective absorption across 1200 nm in the near-infrared (NIR). Upon inducing the phase transition via heating, the absorption resonance is blue-shifted by as much as 60 nm. This process is reversible upon cooling and repeatable over more than ten temperature cycles. Dynamic, ultrathin VO₂ films deposited by ALD, as demonstrated here, open up new potential architectures and applications where VO₂ can be utilized to provide reconfigurability including three-dimensional, flexible and large-area structures.Nano lettersActively Tunable Metasurfaces via Plasmonic Nanogap Cavities with Sub-10-nm VO₂ Films.PMC9101075FA9550-18-1-0326N00014-17-1-2589W911NF1610471FA9550-21-1-0312Boyce AMShen QAvila JWheeler VDZhang SStewart JWMikkelsen MHfalseActively Tunable Metasurfaces via Plasmonic Nanogap Cavities with Sub-10-nm VO₂ Films.Actively tunable optical materials integrated with engineered subwavelength structures could enable novel optoelectronic devices, including reconfigurable light sources and tunable on-chip spectral filters. The phase-change material vanadium dioxide (VO₂) provides a promising solid-state solution for dynamic tuning; however, previous demonstrations have been limited to thicker and often rough VO₂ films or require a lattice-matched substrate for growth. Here, sub-10-nm-thick VO₂ films are realized by atomic layer deposition (ALD) and integrated with plasmonic nanogap cavities to demonstrate tunable, spectrally selective absorption across 1200 nm in the near-infrared (NIR). Upon inducing the phase transition via heating, the absorption resonance is blue-shifted by as much as 60 nm. This process is reversible upon cooling and repeatable over more than ten temperature cycles. Dynamic, ultrathin VO₂ films deposited by ALD, as demonstrated here, open up new potential architectures and applications where VO₂ can be utilized to provide reconfigurability including three-dimensional, flexible and large-area structures.2022-01-01T00:00:00Z2022 May2025-04-04T18:39:30.36Z2025-02-19T00:55:51.205ZS-EPMC91010753547226110.1021/acs.nanolett.1c04175