Studies of Nanoparticle-Assisted Photoannealing of Polydimethylsiloxane by Time-harmonic Photothermal Microscopy
Studies of Nanoparticle-Assisted Photoannealing of Polydimethylsiloxane by Time-harmonic Photothermal Microscopy
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时谐光热显微镜研究聚二甲基硅氧烷纳米颗粒辅助光退火
DOI：
10.1021/acsphotonics.0c00968
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发表时间：
2020
期刊：
影响因子：
7
通讯作者：
Dragnea, Bogdan
中科院分区：
文献类型：
--
作者：
Zahedian, Maryam;Lee, Zachary;Koh, Eun Sohl;Dragnea, Bogdan
在纳米粒子辅助光热显微镜中，纳米粒子吸收辐射后会发生非辐射弛豫，导致周围介质温度、压力和密度的变化。在谐波调制辐照下，有限的热扩散速率导致介质中某个位置的热振荡相对于纳米颗粒表面的热振荡之间存在相位延迟。相位延迟在探测激光体积上的平均值可以与探测到的探测功率调制幅度一起测量。在这项研究中，我们表明，结合更广泛的调制幅度测量，光热相可以提供一个互补的，敏感的探针，热诱导局部介质性质的变化。作为原理证明，我们研究了一种广泛使用的，技术上重要的聚合物抗蚀剂：聚二甲基硅氧烷（PDMS）。此外，我们还展示了如何在模拟的帮助下，从相位/振幅数据中提取光退火介质的温度依赖特性。
In nanoparticle-assisted photothermal microscopy, absorption of radiation by a nanoparticle is followed by nonradiative relaxation, which leads to changes in the surrounding medium temperature, pressure, and density. Under harmonically modulated irradiation, the finite heat diffusion rate causes a phase delay between the thermal oscillation at a location in the medium relative to that at the nanoparticle surface. The phase delay averaged over the probe laser volume can be measured concomitantly with the amplitude of detected probe power modulation. In this study we show that, in conjunction with the more widespread measurement of the modulation amplitude, the photothermal phase can provide a complementary, sensitive probe of thermally induced changes in the local medium properties. As proof of principle, we study a widely used, technologically important polymer resist: polydimethylsiloxane (PDMS). In addition we show how, with the help of simulations, it is possible to extract from phase/amplitude data the temperature-dependent properties of the photoannealed medium.