Study of the Electronic Structures of Organic Solids by Inverse Photoemission Spectroscopy

逆光电发射光谱是一种检测固体电子结构的强大技术，它通过测量电子撞击固体样品所产生的高能光子的发射来检测固体的电子结构。在本研究项目中，我们构建了一个逆光发射光谱仪，用于研究有机固体中空电子态的结构，这方面的研究以前很少。我们咨询了东京大学的研究小组，设计了光谱仪。他们已经建造了自己的光谱仪。特别注意设计一种仪器，适合研究有机和无机固体。到1991学年开始的时候。我们完成了真空室、电子枪部件、光探测系统和电子系统的构建。我们还开发了处理收集数据的软件。将这些部件组装在一起，然后进行真空测试，激活…更多的离子和调整电子枪，以及其他调整。在这些工作完成后，对蒸发金薄膜的逆光发射光谱进行了测量，以检验仪器的性能，所得光谱与文献报道的光谱吻合良好。随着光谱仪的成功构建，我们开始了对半导体Te、SnTe和PbTe的逆光发射光谱的测量，这是以前没有报道的。所得的光谱给出了这些材料的空态电子结构的信息。然后我们测量了具有代表性的有机固体：苯和酞菁的逆光发射光谱，得到了这些材料的电子结构的信息，如最低空轨道的能量。虽然还存在一些实验问题。本研究为更详细地了解有机固体的电子结构开辟了一条道路。少

Inverse photoemission spectroscopy is a powerful technique for examining the electronic structures of solids by measuring the emission of high energy photons caused by impinging electrons into the solid sample. In this research project, we have constructed an inverse photoemission spectrometer for studying the structure of the vacant electron-ic states in organic solids, about which only little information have been studied previously. We designed the spectrometer consulting with the groups of Tokyo University. Who have already constructed their own spectrometer. Special care was paid for designing an instrument suitable for studying both organic and inorganic solids. By the beginning of the academic year of 1991. We completed the construction of the vacuum chambers, parts for the electron gun, light detection system, and the electronics system. Also we have developed the software for handling the collected data. These parts were assembled together, followed by the vacuum test, activat … More ion and adjustment of the electron gun, and other adjustments. After these things were finished satisfactory, the inverse photoemission spectra of evaporated gold films were measured for examining the performance of the instrument, giving spectra in good agreement with those reported in the literature. With establishing the successful construction of the spectrometer, we proceeded in measuring the inverse photoemission spectra of the semiconductors Te, SnTe, and PbTe, for which no previous reports are available. The obtained spectra give information about the electronic structures of the vacant states of these materials. Then we have measured the inverse photoemission spectra of representative organic solids : benzene and Cuphthalocyanine, which gave information about the electronic structures of these materials such as the energy of the lowest vacant orbitals. Although there still exist several experimental problems. The present study opened a way for more detailed understanding of the electronic structures of organic solids. Less