Year: 2025
Type: article
Abstract: Tuning the spectral and directional characteristics of thermal emission is critical for advancing technologies such as thermophotovoltaics (TPVs), passive thermal radiative cooling (PTRC), and solar thermophotovoltaics (STPVs), yet scalable fabrication methods remain limited. Here, femtosecond laser surface processing (FLSP), a top‐down ablation and re‐solidification approach is employed, to create mound‐shaped surface microstructures on titanium (Ti) surfaces. By varying laser fluence and pulse count, spectrally selective and omnidirectional high emissivity (⩾0.9) in the mid‐infrared range (7.5–14 µm) is achieved, which increases with structure height. To understand the underlying physics, finite element modeling (FEM) is conducted, guided by structural and optical parameters extracted using Mueller matrix spectroscopic ellipsometry and modeled via the anisotropic Bruggeman effective medium approximation. Simulations reveal that height, base length, periodicity, and oxide shell contribute to the emergence of plasmonic and interband resonance modes spanning the UV to mid‐IR range. Comprehensive material characterizations, including SEM, FIB‐EDS, and XPS, confirm the formation of a conformal Ti–TiO x core‐shell interface, which activates mid‐IR resonance modes in agreement with FEM predictions. The proposed Ti‐based metamaterial platform provides a scalable strategy for engineering thermal emission in next‐generation energy systems.
Source: Advanced Optical Materials
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,880
Funders: National Science Foundation, National Aeronautics and Space Administration, Nebraska Space Grant Consortium, J. A. Woollam Foundation, Nuclear Safety and Security Commission, Division of Materials Research, Division of Civil, Mechanical and Manufacturing Innovation, Division of Electrical, Communications and Cyber Systems, Office of Experimental Program to Stimulate Competitive Research, Materials and Manufacturing Directorate
Awards: MRSEC: Polarization and Spin Phenomena in Nanoferroic Structures (P-SPINS), G1263877917, G1286853602, G1318668994, The influence of doping and annealing onto the lattice dynamics, band structure and free charge carrier properties in monoclinic gallium aluminum oxide semiconductor alloys, G1490070297, NNCI: Nebraska Nanoscale Facility (NNF), G1663779495, G1749235917, G2441746960, G2501386473, G2621181266, G2726307718, G2999142486, G3033020585, G3752271503, G3780816079, G3908297474, Semiconductor-based Terahertz Traveling Wave Amplifiers for Monolithic Integration, G465234751, Broadband and tunable enhanced chiral light-matter interactions at the visible with new ultrathin helical metamaterials, NSF-DFG: Advances in Ion-Surface Interaction-Driven Manufacturing of One-Dimensional Metal Oxide Heterostructures, G6848461113, RII Track-1: Emergent Quantum Materials and Technologies (EQUATE), G8765119500, G918104398
OpenAlex ID: W4413852302