Photoelectron Yield Spectroscopy as a Tool to Examine Electronic Structures
报告题目：Photoelectron Yield Spectroscopy as a Tool to Examine Electronic Structures
报告人：Prof. Hisao Ishii, Chiba University
报告人简介：Prof. Hisao Ishii received his MS and Ph.D. degrees in chemistry from the University of Tokyo, in 1988 and 1991, respectively.His thesis research focused on the metastable atom electron spectroscopy of clean and adsorbate-covered silicon surfaces. In 1991, he started to
investigate the film and interface electronic structure of organic semiconductors at Nagoya University as an assistant professor. In 2002, he was promoted to associate professor in Research Institute of Electrical Communication, Tohoku University, to extend his research to organic device physics. Now, he has been working for Chiba University since 2006 as a professor. His current research interests include photoelectron spectroscopy of functional organic materials,electronic structure of organic/inorganicinterfaces, and molecular orientation of thin organic films. His efforts are also focusing on developing new techniques such as photoelectron yield spectroscopy, high-sensitivity photoelectron spectroscopy and rotary Kelvin probe, etc.
报告简介：Photoelectron yield spectroscopy (PYS), in which total photoelectron yield is recorded as a function of incident photon energy, has been widely applied to determine the ionization energy of various electronic materials. PYS has some advantages complimentary to conventional photoelectron spectroscopy; (i) the measurement environment is not limited to vacuum, (ii) the sample charge-up problem is practically negligible, (iii) high sensitivity is available in vacuum, and so on. Thus, PYS is a powerful method to explore the electronic structures of organic materials and interfaces in practical situation. In this lecture, first we describe the basic principle and experimental setup of PYS. Then the applications to various organic materials and interfaces are described with the results of combined application of PYS and high-sensitivity photoemissionspectroscopy. In addition, operando PYS measurement using organic transistor device is also reported in relation to anion state. Finally, constant final state photoelectron yield spectroscopy (CFS-YS), in which the partial photoelectron yield for a fixed kinetic energy is recorded as a function of photon energy, is introduced as a tool to examine the density of states of semiconductors in high sensitivity.