| There is a significant difference between the physical property of surface and bulk material.In recent years,scientists have developed numerous of techniques such as atomic force microscope(AFM),near-field scanning optical microscope(SNOM)that to research surface physics.Scanning probe electron energy spectrometer(SPEES)which combines scanning tunneling microscope(STM)with electron energy spectroscopy is an emerging technology.Using this technology we can not only analyse the surface topography,but also get the electron energy loss spectrum on specific area of the sample surface in situ.The first chapter briefly introduces the development of solid surface research and reviews the scanning probe electron spectroscopy.It introduces the spectrometers built by other research groups and the relevant experimental results are also be discussed.At the same time,it also outlines the nonlinear electron scattering phenomenon(NES)found in our laboratory.The second chapter mainly introduces the physical structure of the new genera-tion SPEES which includes:STM system,double toroidal electron energy analyser,power supply system and data acquisition system.The improvement of the spectrom-eter focuses on the following three aspects:first,the new micro-electrode shield tip production process;second,the improvement of the sample preparation process;third,the improvement of tip-sample distance control program.These three improvements are mainly used to improve the spatial resolution of our spectrometer.The distance between the field emission tip and the sample needs to be close enough to achieve the desired spatial resolution.micro-electrode shield tip can solve this problem.In this chapter,the production process of the micro-electrical shield tip and the test results of its performance are introduced in detail.In addition,it also introduces the making pro-cess of the specific grating sample and the corresponding electron energy loss spectrum measurement results are also shown in this chapter.The third chapter introduces the study on NES of Ag and Au nanostructure on HOPG substrates.In the experiment on Au samples,we verify the NES process again,and prove the universality of this phenomenon in the excitation process of surface plas-mon(SP)of metal nano-structures.In the experiment of the Ag sample,we prepared the non-isotropic Ag nanostructures to carry out the study on angular distribution of NES.The experimental results show that for non-isotropic Ag nanostructures,the probabil-ity of SP excited by electron scattering has obvious angular distribution.A maximum value was observed in the direction matching SP oscillating pattern.Due to the effect of the NES process,the excitation probability is greatly increased.It is possible to de-velop a new highly localized directional electron source,which has a profound impact on surface physics.The fourth chapter introduces the related research of scanning probe electron spec-troscopy based on the new generation of SPEES,which includes:first,the excitation intensity of the surface plasma under different coating or annealing condition.Finally,based on the surface roughness of the sample,we determined an optimal sample prepara-tion condition.Second,we hope to develop a new spectral technology based on the NES phenomenon.Using the electric field induced by SP to ionize the adsorbed molecules to obtain the information similar to the photoelectron spectrum.We choose porphyrin molecules as adsorption molecules.I use the GAUSSIAN program to calculate the electronic structure of porphyrin molecules,I also design the organic vapor deposition device.Third,We measure the Low energy secondary electron spectrum of Ag nanos-tructures,the experimental results are introduced in detail,and this spectrum can be used as the background of the SP photoelectron spectrum introduced above.Chapter five introduces the electron momentum spectroscopy(EMS)study of outer valence electronic structure of pyrrole.The last part is about the conclusion of my work and the prospect of future research. |
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