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arXiv 2203.15922cond-mat.mtrl-sci
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近红外光催化金属中的高效热载流子动力学

Efficient hot carrier dynamics in near-infrared photocatalytic metals

Cesar E. P. Villegas, Marina S. Leite, Andrea Marini, A. R. Rocha

摘要:

光激发金属可以产生高能热载流子,其受控产生和提取是技术应用的一个有前途的途径。虽然Au族金属中的热载流子动力学已被广泛研究,但在中红外和近红外Pt族金属范围内的光激发载流子动力学的微观描述仍然很少。由于这些材料广泛用于催化,最近,在等离子体催化,其微观载体动力学特性是至关重要的。我们采用\emph{ab initio}多体微扰理论研究了体相Pd和Pt中的热载流子产生、弛豫时间和平均自由程。我们发现,在这种金属中的光激发载流子的直接光学跃迁主要产生在近红外范围。我们还发现,电子-声子质量增强参数Pt是16 $\%$高于Pd,这一结果有助于解释几个实验结果显示出不同的趋势。此外,我们预测Pd(Pt)热电子具有高达35 fs(24 fs)的总弛豫时间,发生在约0.5 eV(1.0 eV)以上的费米能量。最后,当受到范围从0.4到1.6 eV的激发能时,可以在Pd(110)和Pd(100)的纳米膜中实现有效的热电子产生和提取。

英文摘要:

Photoexcited metals can produce highly-energetic hot carriers whose controlled generation and extraction is a promising avenue for technological applications. While hot carrier dynamics in Au-group metals have been widely investigated, a microscopic description of the dynamics of photoexcited carriers in the mid-infrared and near-infrared Pt-group metals range is still scarce. Since these materials are widely used in catalysis and, more recently, in plasmonic catalysis, their microscopic carrier dynamics characterization is crucial. We employ \emph{ab initio} many-body perturbation theory to investigate the hot carrier generation, relaxation times, and mean free path in bulk Pd and Pt. We show that the direct optical transitions of photoexcited carriers in this metals are mainly generated in the near-infrared range. We also find that the electron-phonon mass enhancement parameter for Pt is 16 $\%$ higher than Pd, a result that help explains several experimental results showing diverse trends. Moreover, we predict that Pd (Pt) hot electrons possess total relaxation times of up to 35 fs (24 fs), taking place at approximately 0.5 eV (1.0 eV) above the Fermi energy. Finally, an efficient hot electron generation and extraction can be achieved in nanofilms of Pd (110) and Pd (100) when subject to excitation energies ranging from 0.4 to 1.6 eV.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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