Mg Capping Inside p-Tert-butylcalix[4]arene Adsorbed on a Ge(100) Surface

The Mg capping inside p-tert-butylcalix[4]arene (p-TBCA) adsorbed onto a Ge(100) surface was investigated using high-resolution photoemission spectroscopy (HRPES) and their corresponding DFT calculation results. After 0.10 ML p-TBCA molecules had been adsorbed onto a Ge(100) surface, subsequent adsorption of a small amount of metallic Mg (similar to 0.10 ML) resulted in the formation of a capped structure inside the preadsorbed p-TBCA molecules. The adsorption structures resulting from further deposition of Mg (similar to 0.50 ML) onto the Ge(100) surface were monitored based on the surface charge state obtained from Mg 2s core level spectrum. We also clarified the evidence of the Mg capped inside p-TBCA adsorbed onto the Ge(100) surface as we monitored the work function change. Moreover, we confirmed that three different adsorption structures are experimentally favorable at room temperature through DFT calculation results.