Surface Effects on Catechol/Semiconductor Interfaces

We present a density functional investigation of the surface effects on the catechol sensitization of selected hexagonal semiconductors (SiC, GaN, InN, CdS, CdSe). The atomic relaxation, the ionicity, and the reactivity, which characterize the selected substrates, are found to crucially influence both the bonding geometry and the electronic level alignment at the interface. Our results indicate that surface effects must be considered in order to obtain a correct picture of the optoelectronic response of the system. Our findings pave the way to the fundamental understanding and future design of hybrid catecholate materials for optoelectronic and biomedical applications.