• 文献标题:   Laboratory-based real and reciprocal space imaging of the electronic structure of few layer graphene on SiC(000(1)over-bar) using photoelectron emission microscopy
  • 文献类型:   Article, Proceedings Paper
  • 作  者:   BARRETT N, WINKLER K, KROMKER B, CONRAD EH
  • 作者关键词:   peem, laboratory he source, energy filtering, reciprocal space imaging, light polarization, dark field, graphene
  • 出版物名称:   ULTRAMICROSCOPY
  • ISSN:   0304-3991
  • 通讯作者地址:   CEA
  • 被引频次:   1
  • DOI:   10.1016/j.ultramic.2013.02.010
  • 出版年:   2013

▎ 摘  要

We present real and reciprocal space photoelectron emission microscopy (PEEM) results on few layer graphene using laboratory based He I and II radiation. The combination of a focused high-intensity source and high transmission PEEM electron optics provides good signal to noise ratios for the different modes of acquisition. We demonstrate work function mapping and secondary electron analysis, related to the graphene layer thickness, band structure imaging from micron scale regions by wave vector resolved PEEM (k-PEEM) and local secondary electron spectroscopy, giving information on the valence and conduction band states and the dispersion relations of the pi bands. Dark field PEEM is done by selecting the Dirac cone corresponding to the specific rotation of each graphene layer and allows spatial mapping of the commensurate rotation angles. The use of He II radiation increases the volume of reciprocal space accessible to k-PEEM and improves signal to background. The preferential linear polarization of the light source is used to investigate aspects of the electronic chirality near the Dirac cone. Recent developments in sample manipulation and cooling are presented. (C) 2013 Elsevier BY. All rights reserved.