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

An ultra-thin perfect absorber for deep ultraviolet light was realized using an Al/TiO2/AlN system. The TiO2 thickness was optimized using the Fresnel phasor diagram in complex space to achieve perfect light absorption. As a result of the calculation almost perfect absorption into the TiO2 film was found, despite the film being much thinner than the wavelength. An optimized Al/TiO2/AlN system was fabricated, and an average absorption greater than 97% was experimentally demonstrated at wavelengths of approximately 255-280 nm at normal light incidence. Our structure does not require nanopatterning processes, and this is advantageous for low-cost and large-area manufacturing. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

An ultra-thin perfect absorber for deep ultraviolet light was achieved using an Al/TiO2/AlN system. The TiO2 thickness was optimized to achieve almost perfect light absorption despite the thin film being much thinner than the wavelength. The optimized system demonstrated an average absorption greater than 97% for wavelengths of approximately 255-280 nm at normal light incidence. This structure has the advantage of not requiring nanopatterning processes, making it suitable for low-cost and large-area manufacturing.