Ultra-thin deep ultraviolet perfect absorber using an Al/TiO₂/AlN system

Area of Science:

• Photonics and optical materials science.
• Nanotechnology and thin-film device fabrication.

Background:

• Deep ultraviolet (DUV) light applications require efficient light absorbers.
• Existing DUV absorbers are often bulky or require complex fabrication.
• Developing thin, high-absorption materials for DUV is crucial.

Purpose of the Study:

• To design and demonstrate an ultra-thin perfect absorber for DUV light.
• To optimize the absorber structure for maximum light absorption.
• To enable cost-effective and large-area manufacturing of DUV absorbers.

Main Methods:

• Utilized an Aluminum/Titanium Dioxide/Aluminum Nitride (Al/TiO2/AlN) multilayer system.
• Employed Fresnel phasor diagram analysis in complex space for TiO2 thickness optimization.
• Fabricated the optimized Al/TiO2/AlN structure.

Main Results:

• Achieved near-perfect light absorption in an ultra-thin TiO2 film.
• Experimentally demonstrated an average absorption exceeding 97% for DUV light (255-280 nm).
• The fabricated absorber operates effectively at normal light incidence.

Conclusions:

• The Al/TiO2/AlN system represents a highly efficient ultra-thin DUV perfect absorber.
• The design avoids nanopatterning, facilitating low-cost, large-area production.
• This technology offers a promising solution for DUV light management applications.