Observation of electron distributions on outermost layers of solid surfaces by penning ionization electron spectroscopy

The authors have shown that penning ionization electron spectroscopy (PIES) provides direct information on the electron distribution of the outermost surface layer of the solid and hence is truly sensitive in nature. Ion neutralization spectroscopy (INS), in which rare gas ions are used for the excitation source, is another surface sensitive technique that can be compared with PIES. Sections discussed include the orientation of surface molecules, phase change on the solid surface, adsorption on the solid surface, and chemical change on the surface