Photoemission Study Of The Desorption And Reaction Of C-60 And K4c60 Films On Si(111) Surfaces

X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) have been used to investigate the desorption and reaction of C-60 and K4C60 films on Si(111) surfaces. For C-60/Si system, C-60 multilayers desorb from the surface at 450 K, except the first monolayer. In the case of K4C60/Si system, the desorption of both potassium and C-60 begins at 820 K. The potassium atoms are completely removed from the surface at 1000 K, causing the disruption of C-60 cage structure and the formations of both SiC and C-Si alloy. Although the C 1s peak due to SiC becomes detectable at 950 K in both cases, the SiC intensity converted by C-Si alloy for K4C60/Si system grows faster at temperatures above 1000 K. (C) 1998 Elsevier Science B.V. All rights reserved.