Tunable Narrowband Silicon-Based Thermal Emitter with Excellent High-Temperature Stability Fabricated by Lithography-Free Methods

Abstract

Thermal emitters with properties of wavelength-selective and narrowband have been highly sought after for a variety of potential applications due to their high energy efficiency in the mid-infrared spectral range. In this study, we theoretically and experimentally demonstrate the tunable narrowband thermal emitter based on fully planar Si-W-SiN/SiNO multilayer, which is realized by the excitation of Tamm plasmon polaritons between a W layer and a SiN/SiNO-distributed Bragg reflector. In conjunction with electromagnetic simulations by the FDTD method, the optimum structure design of the emitter is implemented by 2.5 periods of DBR structure, and the corresponding emitter exhibits the nearly perfect narrowband absorption performance at the resonance wavelength and suppressed absorption performance in long wave range. Additionally, the narrowband absorption peak is insensitive to polarization mode and has a considerable angular tolerance of incident light. Furthermore, the actual high-quality Si-W-SiN/SiNO emitters are fabricated through lithography-free methods including magnetron sputtering and PECVD technology. The experimental absorption spectra of optimized emitters are found to be in good agreement with the simulated absorption spectra, showing the tunable narrowband absorption with all peak values of over 95%. Remarkably, the fabricated Si-W-SiN/SiNO emitter presents excellent high-temperature stability for several heating/cooling cycles confirmed up to 1200 K in Ar ambient. This easy-to-fabricate and tunable narrowband refractory emitter paves the way for practical designs in various photonic and thermal applications, such as thermophotovoltaic and IR radiative heaters.

Silicon-based spectrally selective emitters with good high-temperature stability on stepped metasurfaces

“…The details of the above two spectrophotometers have been described in our previous work. 54 Thermal annealing experiments were performed using a tube furnace (OTF-1200X-80-II).…”

Spectrum‐Selective High‐Temperature Tolerant Thermal Emitter by Dual‐Coherence Enhanced Absorption for Solar Thermophotovoltaics

“…Because a high-quality Lorentzian line-shape emission spectrum cannot compensate for the insufficient emission power caused by compression of the emission in wavelength, [12,48] it leads to a decline in efficiency. Additionally, if the emission spectrum is widened (the quality factor decreases) as in the metasurface-based emitters, [49,50] the Tamm-plasmonbased emitters, [33,51,52] and the CPA-based emitters, [47,53,54] the total system efficiency will be relatively adversely affected compared to the step-function-like spectrum of the thermal emitter because of the tail of spectrum in mid-infrared. If there is a unimodal emission state whose eigenfrequency is certain both in real and imaginary parts (the real part relates to the center frequency of the absorption, and the imaginary part relates to the quality factor) where most of the photon energy is above the bandgap, a Lorentzian line shape shows in emission as shown in Figure 1b.…”

Nanolayered Wavelength-Selective Narrowband Thermal Emitters for Solar Thermophotovoltaics

“…However, the fabricated emitter has a high secondary peak in the longer wavelength region and exhibits poor thermal stability. In a previous study, 26 we designed a TPP-based thermal emitter composed of SiN x / SiN y O z (SiN/SiNO) multilayers and a tungsten (W) film on a silicon (Si) substrate. The proposed emitter achieves nearly unity absorption at the expected wavelength.…”