Characteristics of Si(111) surface with embedded C84 molecules

Abstract

A monolayer of fullerene molecules on Si(111) surfaces is fabricated in an ultrahigh vacuum chamber through a controlled self-assembly process. The characteristics of self-assembled Si(111) surfaces, including supramolecular structures, electronic density of states, the quantum confinement effect, field emission features, and optoelectronical properties with embedded C₈₄ are determined by the use of an ultrahigh vacuum scanning probe microscope. The results revealed that such a silicon surface with embedded C₈₄ has a wide band gap of ∼3.4 eV, high emission efficiency and low turn-on voltage, all of which are crucial to nano-electronics, optoelectronics, and the fabrication of semiconductor carbide. The measured data derived from photoluminescence emission experiments further confirm the corresponding band gap value obtained from I–V curves. The theoretical results from first-principles calculations for the field enhancement factor are compared with experimental measurements.