Hot Electron Luminescence from Metal and Semiconductor Nanoparticles and Its Applications

Abstract

Abstract The recent advances in the study of the hot electron luminescence from metal and semiconductor nanoparticles are discussed. The luminescence from the plasmonic hot spots created in metal nanoparticles and nanostructures is attributed to hot electron intraband luminescence, which is quite similar to blackbody radiation. Since the plasmonic hot spots are sensitive to polarization and wavelength of excitation light, such hot electron intraband luminescence can be employed to realize multidimensional optical data storage with ultralow energy and ultrahigh density. Similar hot electron intraband luminescence was also observed in gallium arsenide and silicon nanoparticles by resonantly exciting their magnetic resonances. It was revealed that the luminescence from gallium arsenide nanoparticles originates from the intraband transition of hot electrons while that from silicon nanoparticles arises from the interband transition of hot electrons assisted by phonons. The different band structures of gallium arsenide and silicon are responsible for the different types of hot electron luminescence observed in gallium arsenide and silicon nanoparticles. It was found that the Auger effect, which is dramatically enhanced by high carrier density, increases the relaxation time of hot electrons within the conduction band, leading to an enhancement in the quantum efficiency by four to five orders of magnitude. The achievement of efficient hot electron luminescence with a broadband indicates that silicon‐based photonic devices integrated with silicon nitride–based optical circuits can be realized by exploiting the Mie resonances in silicon nanoparticles.