Dynamics of surface electronic excited states

1. CO在Ni（111）和NiO（111）表面瞬态吸附行为的时间分辨SFG观测研究了CO/Ni（111）和CO/NiO（111）体系在紫外和可见皮秒激光脉冲激发下的瞬态SFG谱。结果表明，在紫外光脉冲辐照下，出现了寿命小于30 ps的瞬态振动手。结果表明，紫外光脉冲产生的衬底热电子通过电子驱动过程激发了CO伸缩振动模.用时间分辨SFG方法研究了强近红外脉冲辐照在甲酸盐吸附Ni（111）和NiO（111）表面产生的瞬态物种。发现不稳定的单齿甲酸盐作为分解反应的中间产物出现.弛豫动力学 ...更多信息 用皮秒红外泵浦-探测法测定了吸附在沸石OH基上的物种的振动寿命。观察到了吸附水分子的IVR过程，随后是分子筛骨架低频声子模的能量弛豫过程，并测量了振动寿命.萘在Ni（111）表面上吸附的准分子寿命测量了萘在Ni（111）表面上吸附膜的荧光寿命随厚度的变化。当厚度小于50 nm时，由于萘激基缔合物与Ni表面之间的像偶极相互作用，寿命表现出强烈的厚度依赖性.苯和萘吸附Cu（111）表面电子激发态的二次谐波测量在苯/Cu（111）和萘/Cu（111）体系上测量了共振二次谐波谱。对于这两种情况，由于分子的激发态与Cu（111）表面的表面态之间的相互作用，共振峰相对于自由分子的共振频率均出现蓝移. CdO薄膜的热电子动力学研究在重掺杂n型CdO薄膜上进行了飞秒泵浦-探测实验。在衬底温度为30 K时，观察到了紫外飞秒脉冲产生的超热电子的热化过程，并估算了电子-晶格热化的时间常数为22 ps。少

1. Time-resolved SFG observation of transient behavior of CO adsorbed on Ni(111) and NiO(111) surfacesTransient SFG spectra on CO/Ni(111) and CO/NiO(111) systems under the irradiation by UV and visible picosecond laser pulses as the excitation pulse was measured. It was found that the transient vibrational hand with the lifetime shorter than 30 ps was appeared when the UV pulses was irradiated. The results suggest that the substrate hot electrons generated by the UV pulses could excite the CO stretching vibrational mode by electronic driven process.2. Time-resolved SFG study of short-lived surface species produced by the intense NIR pulsesTransient species on the formate adsorbed Ni(111) and NiO(111) surfaces produced by the temporal temperature increase due to the picosecond NIR pulse irradiation was observed by the time-resolved SFG method. It was found that the unstable monodentate formate was appeared as the intermediates of the decomposition reaction.3. Relaxation dynamics of the … More water molecule adsorbed on the zeolite OH groups.The vibrational lifetimes of the species adsorbed on the zeolite OH group was measured by the picosecond IR pump-probe method. The IVR process in the adsorbed water molecule followed by the energy relaxation process to the low-frequency phonon mode of zeolite framework was observed, and the vibrational lifetimes were measured.4. Excimer lifetime of naphthalene adsorbed on Ni(111) surfaceThe thickness dependence of lifetime of fluorescence from the naphthalene films adsorbed on Ni(111) surface was measured. The lifetime showed the strong thickness dependence when the thickness was less than 50 nm due to the image dipole interaction between the naphthalene excimer and Ni surface.5. SHG measurements of the electronic excited states on benzene and naphthalene adsorbed Cu(111) surfaceResonant SHG spectra were measured on the benzene/Cu(111) and naphthalene/Cu(111) systems. For both cases, the resonant peaks showed the blue shifts compared with the resonant frequency of free molecules due to the interaction between the excited states of the molecules and the surface state of Cu(111) surface.6. Hot electron dynamics of CdO thin filmFemtosecond pump-probe experiments were carried out on the heavily doped n-type CdO thin film. It was observed that the thermalization process of hot electrons generated by the UV femtosecond pulses, and the time constant of electron-lattice thermalization was estimated as 22 ps at the substrate temperature of 30K. Less