SURFACE PROPERTIES OF a-Si : H AND a-Si : F INVESTIGATED BY PHOTOELECTRON SPECTROSCOPY L. Ley, H. Richter, R. Kärcher, R. L. Johnson et J. ReichardtJ. Phys. Colloques, 42 C4 (1981) C4-753-C4-759DOI: https://doi.org/10.1051/jphyscol:19814165