Abstract Cubic Cu2−xSe nanocrystals (NCs) exhibit a strong localized surface plasmon resonance (LSPR) absorption in the near-infrared (NIR) region, in which the LSPR wavelength and stability are significant for the NIR-region applications in photo-thermal therapy and photoacoustic imaging. Herein, we have systematically studied the effects of surface ligands with varying the feeding ratio of oleylamine (OM) to oleic acid (OA) on LSPR behavior and stabilization of Cu2−xSe NCs, which were synthesized by using a typical hot-injection method. The LSPR wavelength of the as-obtained Cu2−xSe NCs could be tuned from 1260 to 1030 nm with an increase of the feeding ratio of OM to OA. Furthermore, these Cu2−xSe NCs showed different LSPR stability with varying feeding ratios of OM to OA. For the Cu2−xSe NCs synthesized in the presence of only OM, the LSPR could keep stable basically after exposure to air for 60 days. However, in the feeding ratio of OM to OA of 7:3 and 5:5 cases, the LSPR extinction spectra showed an obvious blue-shift in the wavelength. The characterized results indicated the different surface ligands had significant effects on the LSPR behavior and stabilization, and the LSPR change was in good agreement with the calculated results based on the Mie-Drude model. This work provides a new research idea for tuning the LSPR behavior of copper chalcogenide NCs.

中文翻译：

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表面配体对Cu2-xSe纳米晶局域表面等离子体共振和稳定性的影响

摘要 立方 Cu2−xSe 纳米晶体 (NCs) 在近红外 (NIR) 区域表现出强烈的局域表面等离子体共振 (LSPR) 吸收，其中 LSPR 波长和稳定性对于光热治疗中的 NIR 区域应用很重要。和光声成像。在此，我们系统地研究了表面配体随着油胺 (OM) 与油酸 (OA) 进料比的变化对 LSPR 行为和 Cu2-xSe NCs 稳定性的影响，Cu2-xSe NCs 是通过典型的热注射方法合成的。所获得的 Cu2-xSe NCs 的 LSPR 波长可以从 1260 nm 调谐到 1030 nm，随着 OM 与 OA 的进料比的增加。此外，这些 Cu2-xSe NCs 显示出不同的 LSPR 稳定性，具有不同的 OM 与 OA 的进料比。对于仅在 OM 存在下合成的 Cu2-xSe NC，LSPR暴露在空气中60天后基本保持稳定。然而，在 OM 与 OA 的进料比为 7:3 和 5:5 的情况下，LSPR 消光光谱显示出明显的波长蓝移。表征结果表明，不同的表面配体对LSPR行为和稳定性有显着影响，LSPR变化与基于Mie-Drude模型的计算结果吻合良好。这项工作为调节铜硫属化物NCs的LSPR行为提供了新的研究思路。表征结果表明，不同的表面配体对LSPR行为和稳定性有显着影响，LSPR变化与基于Mie-Drude模型的计算结果吻合良好。这项工作为调节铜硫属化物NCs的LSPR行为提供了新的研究思路。表征结果表明，不同的表面配体对LSPR行为和稳定性有显着影响，LSPR变化与基于Mie-Drude模型的计算结果吻合良好。这项工作为调节铜硫属化物NCs的LSPR行为提供了新的研究思路。