State-specific ion desorption from DCOO/Si(100) by C 1s core excitation

摘要

Photon-stimulated ion desorpsion from deuterated formic acid chemisorbed on Si(100) has been studied using pulsed synchrotron radiation by state-selective C 1s core excitation. It is clearly seen that state-specific ion desorption occurs. The D~+ and CDO~+ ion yields are shown to strongly depend on σ~*(C-D) and σ~*(C-O) excitation, respectively. The peak energy shifts in ion yield curves are observed. The third peak shifts of D~+ and CD~+ ion yields could be assigned to doubly electron excitations having small cross sections. Each excited state nature which contributes to ion desorption is discussed.