Pixel-level metal blackbody microcavities via hierarchical laser writing.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40020051.
- Also identified by DOI 10.1126/sciadv.adu0608 and PMC identifier 11870063.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Conventional blackbody cavities, known for their near-unity broadband omnidirectional emissivity (absorptivity), are however constrained by their large volume (e.g., >10<sup>4</sup> cm<sup>3</sup>), imposing crucial restrictions on integration with existing devices. Here, we introduce the concept of metal blackbody microcavities, comprising thousands of microscale periodic pores created on metals, demonstrating excellent emissivity across visible and infrared (IR) ranges (exceeding 0.94 on average from 0.25 to 20 μm). In the long-wavelength IR (8 to 14 μm) region, near-unity emissivity was successfully achieved by 100-μm-deep metal microcavities with ultralow structural aspect ratios, facilitated by laser-textured multiscale surface morphologies that substantially enhance the light-trapping capabilities. Our findings demonstrate that microcavity-based patterns can produce local emissivity, tunable radiative intensity gradients, wide-angle feasibility, and high-temperature resistance, thereby enabling diverse applications in thermal IR displays such as thermal illusion, IR encryption, and grayscale thermal imaging. Notably, these blackbody microcavities are applicable to various metals, presenting considerable potential for use in extreme environments.