Figure 1
2PPE of 1 ML C60 on HOPG.
(a) hν dependences of 2PPE spectra for 1 ML C60 film on HOPG aligned with Efinal, where the hν range was 4.13‒4.77 eV. (b) Energy positions of 2PPE structures including the onset of H against hν, which are assignable to the slope of “0 hν”, “1 hν”, or “2 hν”. Factors obtained by liner fits of the plots are indicated nearby the data. The dotted line shows the “1 hν” slope by an unoccupied level at EF + 1.8 eV (see text). (c) Total 2PPE yield integrated whole energy region versus hν in which the maximum is corresponding to that optical absorption (1T1u) of C60 film. Note that recovering intensity at the highest hν is due to a contribution of one photon photoemission.
