Adsorbed states of cyclopentene, cyclohexene, and 1,4-cyclohexadiene on Si(1 0 0)(2×1): towards the fabrication of novel organic films/Si hybrid structures

In order to fabricate atomically controlled organic materials on Si surfaces, the electronic states of unsaturated cyclic hydrocarbons chemisorbed on Si(1 0 0)(2×1) surfaces were investigated by synchrotron radiation ultraviolet photoelectron spectroscopy (UPS) as a fundamental study. For cyclopentene and cyclohexene, the CC bond interacts with the Si dimer, resulting in the formation of di-σ SiC bonds. In the case of 1,4-cyclohexadiene, on the other hand, one of two CC bonds reacts with the Si dimer and another CC bond remains unreacted with the Si surface. This intact CC bond may introduce the possibility of subsequent functionalization of the organic film, and for the fabrication of atomically controlled and highly functional organic film/Si devices.