论文标题
探测双向等离子体耦合诱导的热电载体在双质量AU/CUS纳米晶体中
Probing Bidirectional Plasmon-Plasmon Coupling-Induced Hot Charge Carriers in Dualplasmonic Au/CuS Nanocrystals
论文作者
论文摘要
异质结构的AU/CUS纳米晶体（NCS）表现出以两个不同的波长（551 nm和1051 nm）为中心的局部表面等离子体共振（LSPR），与各自同质的AU AU和CUS NC光谱相比，它们略有扩展。通过应用超快瞬态吸收光谱（TAS），我们表明，异质结构的AU/CUS NCS的相应LSPR最大值的共振激发导致两种情况下与这两种LSPR相关的特征性热载体松弛。双重异质结构行为与同型AU和CUS NCS的胶体混合物的比较表明，耦合的双质子相互作用仅在异质结构的AU/CUS NC中活跃。通过研究该过程的电荷载体动力学，我们发现观察到的相互作用是基于电荷载体，因为它比音调或热过程快（<100 fs）。对于异质化的纳米晶体而言，生成的热荷载体的松弛速度更快，这也表明该相互作用是作为能量传递或两种材料之间的荷载载流子传递而发生的。我们的结果加强了对异质化Au/cus NC中多层次相互作用的理解，并将在这些相互作用是必不可少的情况下显着推动应用，例如催化反应。
Heterostructured Au/CuS nanocrystals (NCs) exhibit localized surface plasmon resonance (LSPR) centered at two different wavelengths (551 nm and 1051 nm) with a slight broadening compared to respective homostructured Au and CuS NC spectra. By applying ultrafast transient absorption spectroscopy (TAS) we show that a resonant excitation at the respective LSPR maxima of the heterostructured Au/CuS NCs leads to the characteristic hot charge carrier relaxation associated with both LSPRs in both cases. A comparison of the dualplasmonic heterostructure behavior with a colloidal mixture of homostructured Au and CuS NCs shows that the coupled dualplasmonic interaction is only active in the heterostructured Au/CuS NCs. By investigating the charge carrier dynamics of the process, we find that the observed interaction is charge carrier based as it is faster than phononic or thermal processes (< 100 fs). The relaxation of the generated hot charge carriers is faster for heterostructured nanocrystals, also indicating, that the interaction occurs as an energy transfer or charge carrier transfer between both materials. Our results strengthen the understanding of multiplasmonic interactions in heterostructured Au/CuS NCs and will significantly advance applications where these interactions are essential, such as catalytic reactions.
