Extracting quantitative dielectric properties from pump-probe spectroscopy.
Extracting quantitative dielectric properties from pump-probe spectroscopy.
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DOI：
10.1038/s41467-022-29112-y
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发表时间：
2022-03-17
影响因子：
16.6
通讯作者：
Rao A
中科院分区：
文献类型：
--
作者：
Ashoka A;Tamming RR;Girija AV;Bretscher H;Verma SD;Yang SD;Lu CH;Hodgkiss JM;Ritchie D;Chen C;Smith CG;Schnedermann C;Price MB;Chen K;Rao A
光学泵浦-探测光谱是研究非平衡电子动力学的有力工具，在从物理和化学到材料科学和生物学的一系列领域中有着广泛的应用。然而，传统的泵浦-探测光谱的缺点是，光致变化的透射，反射和散射可以同时有助于测量的差分光谱，导致在分配的光谱特征的起源和排除定量解释的光谱的模糊性。理想情况下，这些方法将测量潜在的介电函数（或复折射率），然后直接提供关于瞬态激发态动力学的定量信息，而不存在这些模糊性。在这里，我们提出并测试一个模型独立的路线来转换差分透射或反射光谱，通过传统的光学泵浦-探测光谱测量，在定量瞬态介电函数的变化。我们基准这种方法对真实的折射率的变化，使用时间分辨频域干涉测量在原型无机和有机半导体薄膜。我们的方法可以应用到现有的和未来的泵浦探测数据集，允许一个明确的和定量的表征材料的瞬态光激发光谱。这反过来又将加速采用泵浦探测光谱作为一种简单而强大的材料表征和筛选工具。光诱导的透射、反射和散射的变化阻止了传统的泵浦-探测光谱学明确地指定光谱特征的来源。Ashoka等人开发了一种光学建模技术，从标准泵浦-探测测量中提取介电函数的定量和明确变化。
Optical pump-probe spectroscopy is a powerful tool for the study of non-equilibrium electronic dynamics and finds wide applications across a range of fields, from physics and chemistry to material science and biology. However, a shortcoming of conventional pump-probe spectroscopy is that photoinduced changes in transmission, reflection and scattering can simultaneously contribute to the measured differential spectra, leading to ambiguities in assigning the origin of spectral signatures and ruling out quantitative interpretation of the spectra. Ideally, these methods would measure the underlying dielectric function (or the complex refractive index) which would then directly provide quantitative information on the transient excited state dynamics free of these ambiguities. Here we present and test a model independent route to transform differential transmission or reflection spectra, measured via conventional optical pump-probe spectroscopy, to changes in the quantitative transient dielectric function. We benchmark this method against changes in the real refractive index measured using time-resolved Frequency Domain Interferometry in prototypical inorganic and organic semiconductor films. Our methodology can be applied to existing and future pump-probe data sets, allowing for an unambiguous and quantitative characterisation of the transient photoexcited spectra of materials. This in turn will accelerate the adoption of pump-probe spectroscopy as a facile and robust materials characterisation and screening tool. Photoinduced changes in transmission, reflection and scattering prevent conventional pump-probe spectroscopy to unambiguously assign the origin of spectral signatures. Ashoka et al. have developed an optical modelling technique to extract quantitative and unambiguous changes in the dielectric function from standard pump-probe measurements.
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影响因子：
16.6
作者：
Price MB;Butkus J;Jellicoe TC;Sadhanala A;Briane A;Halpert JE;Broch K;Hodgkiss JM;Friend RH;Deschler F
通讯作者：
Deschler F
影响因子：
8.6
作者：
FROHLICH, D;NOTHE, A;REIMANN, K
通讯作者：
REIMANN, K
影响因子：
4.4
作者：
Alvertis, Antonios M.;Pandya, Raj;Beljonne, David
通讯作者：
Beljonne, David
影响因子：
1.6
作者：
Roeser, CAD;Kim, AMT;Mazur, E
通讯作者：
Mazur, E
影响因子：
5.7
作者：
Deschler, Felix;Price, Michael;Friend, Richard H.
通讯作者：
Friend, Richard H.