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谱学（TRPES）的应用，作为等离子体纳米材料在超高真空（表面）和水溶液中等离子体增强热载流子产生和衰变的探针。这些热载流子经历能量损失，这可以通过能量转移到邻近的分子或材料。TRPES光谱测量将涉及使用飞秒激光器、带有半球形电子能量分析仪的超高真空表面科学设备和带有磁瓶飞行时间电子分析仪的液体微射流设备。将考虑许多不同的等离子体结构，包括胶体纳米粒子和基于电化学生长的金纳米棒阵列的超材料，并使用光学消光光谱结合电磁场模拟的数值模拟进行表征。纳米材料的性质将被调整，以探索光电子发射对表面等离子激元的共振激发和纳米结构几何的依赖。

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.