Dynamic control of a material’s thermal emission
could enable
many emerging applications, such as thermal camouflage and infrared
(IR) display. Low-dimensional carbon nanomaterials have shown great
potential in these applications because of their tuneability in charge
density via static gating or ionic intercalation. Herein, a thermal
emission modulator based on single-walled carbon nanotubes (SWCNTs)
is realized by ionic gating. The Fermi energy of the SWCNTs is shifted
via the adsorption of ions on the surface, and the highest emissivity
is observed at the neutral state while both P-type and N-type SWCNTs
have a reduced emissivity. An emissivity modulation range is achieved
approximately from 0.45 to 0.95 within the electrochemical window
of the used ionic liquid. Thermal camouflage and IR display applications
are then demonstrated by utilizing the tuneable thermal emissivity
of the fabricated SWNCT films. More importantly, a single-layer structure
allows effective dynamic control purely by static gating, without
involving any ion interaction process that may cause structural damage,
as observed in graphene and multi-walled nanotubes. Therefore, the
SWCNT-based IR modulators exhibit long-term stability, with nearly
identical modulation range and response time after 6000 dynamic tuning
cycles, indicating great potential for practical applications.