Abstract
Broadband absorbers, with the simultaneous advantages of thermal stability,
insensitivity to light polarization and angle, robustness against harsh
environmental conditions, and large area fabrication by scalable methods,
are essential elements in (solar) thermophotovoltaics. Compared to the noble
metal and multilayered broadband absorbers, high-temperature refractory
metal-based nanostructures with low-Q resonators are reported less. In this
work, 3D titanium nitride (TiN) nanopillars are investigated for ultrabroadband
absorption in the visible and near-infrared spectral regions with average
absorptivities of 0.94, over a wide range of oblique angles between 0° and
75°. The effect of geometrical parameters of the TiN nanopillars on broadband
absorption is investigated. By combining the flexibility of nanopillar
design and lossy TiN films, ultrabroadband absorption in the visible and nearinfrared
is obtained. A thin layer of hafnium oxide is deposited to enhance the
thermal stability of TiN nanopillars. Finally, the thermal/spectral stability of
the TiN nanopillars is demonstrated after annealing at 1473 K for 24 h while
retaining their structural features. Thus, the TiN nanopillars can provide
excellent opportunities for high-temperature applications, especially solar
thermophotovoltaics.
insensitivity to light polarization and angle, robustness against harsh
environmental conditions, and large area fabrication by scalable methods,
are essential elements in (solar) thermophotovoltaics. Compared to the noble
metal and multilayered broadband absorbers, high-temperature refractory
metal-based nanostructures with low-Q resonators are reported less. In this
work, 3D titanium nitride (TiN) nanopillars are investigated for ultrabroadband
absorption in the visible and near-infrared spectral regions with average
absorptivities of 0.94, over a wide range of oblique angles between 0° and
75°. The effect of geometrical parameters of the TiN nanopillars on broadband
absorption is investigated. By combining the flexibility of nanopillar
design and lossy TiN films, ultrabroadband absorption in the visible and nearinfrared
is obtained. A thin layer of hafnium oxide is deposited to enhance the
thermal stability of TiN nanopillars. Finally, the thermal/spectral stability of
the TiN nanopillars is demonstrated after annealing at 1473 K for 24 h while
retaining their structural features. Thus, the TiN nanopillars can provide
excellent opportunities for high-temperature applications, especially solar
thermophotovoltaics.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | 1700552 |
| Tidsskrift | Advanced Optical Materials |
| Vol/bind | 5 |
| Udgave nummer | 22 |
| Antal sider | 8 |
| ISSN | 2195-1071 |
| DOI | |
| Status | Udgivet - okt. 2017 |