Cardozo de Oliveira E R, Xiang C, Esmann M, Lopez Abdala N, Fuertes M C, Bruchhausen A, Pastoriza H, Perrin B, Soler-Illia G J A A, Lanzillotti-Kimura N D
Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120 Palaiseau, France.
Institute for Physics, Carl von Ossietzky University of Oldenburg, 26129 Oldenburg, Germany.
Photoacoustics. 2023 Mar 4;30:100472. doi: 10.1016/j.pacs.2023.100472. eCollection 2023 Apr.
Ultrahigh-frequency acoustic-phonon resonators usually require atomically flat interfaces to avoid phonon scattering and dephasing, leading to expensive fabrication processes, such as molecular beam epitaxy. Mesoporous thin films are based on inexpensive wet chemical fabrication techniques that lead to relatively flat interfaces regardless the presence of nanopores. Here, we report mesoporous titanium dioxide-based acoustic resonators with resonances up to 90 GHz, and quality factors from 3 to 7. Numerical simulations show a good agreement with the picosecond ultrasonics experiments. We also numerically study the effect of changes in the speed of sound on the performance of the resonator. This change could be induced by liquid infiltration into the mesopores. Our findings constitute the first step towards the engineering of building blocks based on mesoporous thin films for reconfigurable optoacoustic sensors.
超高频声子谐振器通常需要原子级平整的界面来避免声子散射和退相，这导致了昂贵的制造工艺，如分子束外延。介孔薄膜基于廉价的湿化学制造技术，无论是否存在纳米孔，都能产生相对平整的界面。在此，我们报道了基于介孔二氧化钛的声谐振器，其共振频率高达90 GHz，品质因数为3至7。数值模拟与皮秒超声实验结果吻合良好。我们还通过数值研究了声速变化对谐振器性能的影响。这种变化可能是由液体渗入介孔引起的。我们的研究结果是基于介孔薄膜构建可重构光声传感器组件工程的第一步。
