Time-resolved photoelectron spectroscopy of hot carrier decay in gold plasmonic nanostructures

该项目将涉及飞秒时间分辨光电子能谱（TRPES）的应用，作为等离子体增强的热载流子产生和等离子体纳米材料衰变的探针，无论是在真空（表面）和水溶液中。这些热载流子经历能量损失，这可能是通过能量转移到相邻的分子或材料。TRPES光谱测量将涉及使用飞秒激光器，一个带半球形电子能量分析仪的真空表面科学装置和一个带磁瓶飞行时间电子分析仪的液体微喷射装置。将考虑许多不同的等离子体结构，包括基于电化学生长的金纳米棒阵列的胶体纳米颗粒和超材料，并使用消光光谱结合电磁场模拟的数值建模来表征。纳米材料将与属性调整，探索表面等离子体共振激发光电子发射的依赖性，和纳米结构的几何形状。

The project will involve the application of femtosecond time-resolved photoemission spectroscopy (TRPES) as a probe of plasmon-enhanced hot carrier generation and decay in plasmonic nanomaterials, both in ultrahigh vacuum (surfaces) and in aqueous solution. These hot carriers undergo energy loss, which can be via energy transfer to adjacent molecules or materials.The TRPES spectroscopy measurements will involve the use of femtosecond lasers, an ultrahigh vacuum surface science apparatus with a hemispherical electron energy analyser and a liquid-microjet apparatus with a magnetic-bottle time-of-flight electron analyser. A number of different plasmonic architectures will be considered, including colloidal nanoparticles and metamaterials based on arrays of electro- chemically grown gold nanorods, and characterised using optical extinction spectroscopy coupled with numerical modelling of electromagnetic field simulations. Nanomaterials will be fabricated with properties tuned to explore the dependence of photoelectron emission on resonant excitation of surface plasmons, and on nanostructure geometry.