Nanometer-scale characterization of surface materials by STM light emission spectroscopy

Three typical applications of the STM light emission spectroscopy in nanometer-scale characterization of surface materials are reviewed. When electrons (holes) are injected from the tip of a STM to a sample surface, visible light is emitted. Since the beam diameter of electrons from the STM tip is narrower than ∼ 1 nm and moreover the beam energy is very low, one can obtain the light emission spectra of individual nanometer-scale structures without modifying them. By correlating the spectra with the size and shape of the structure, materials information about nanometer-scale individual structures can be obtained.