Organic molecules on diamond (001): a synchrotron Study

Abstract

Diamond is a unique material with numerous exceptional properties. This thesis studies organic molecules adsorbed on diamond (001) surfaces using synchrotron radiation-based spectroscopic techniques and complemented by other surface analytical probes. In the first part of the thesis, the dissimilar structural and electronic properties of bare and hydrogenated diamond surfaces are discussed, which leads to their distinct interactions with organic molecules. In particular, we observed that the chemical reaction with organic molecules can continuously tune the electron affinity and electron emission properties of bare diamond. In the second part, controllable p-type surface transfer doping of hydrogenated diamond (001) by a series of molecular acceptors is demonstrated. The charge transfer, electronic structures and energy level alignments at the interfaces are systematically characterized by synchrotron-based photoemission spectroscopy. This study facilitates better selection of organic molecules as effective surface dopants to engineer the surface conductivity of diamond over a wide range.