Synchrotron Radiation Photoemission Study of Chemisorption and Interaction at the K/InP（100） Interface

The room temperature adsorption of K on p-type InP（100） has been studied with use of synchrotron radiation core-level spectroscopy. From the coverage dependent In 4d and P 2p core-level spectra, we found that in the process or K adsorption on InP（100）, the reaction between K and P is observed and K-P compound is formed. When the K coverage 0 ＞ 210 Sec.,the stable K-P compound is formed. Meanwhile, the peak position and peak shape of P 2p shows no change. No reaction occurs between K and In, and in the process of K adsorption on InP（100） surface, the in of substrate is exchanged into surface by K. The K adsorption leads to band bending: The empty state of dangling bond of in （exchanged by K） was filled by the our-shell electrons of K, formed a half-filled surface state. The fermi-level shift and pinning was caused by this half-filled surface state.