Unveiling Nanometer Scale Extinction and Scattering Phenomena through Combined Electron Energy Loss Spectroscopy and Cathodoluminescence Measurements

Abstract

Plasmon modes of the exact same individual gold nanoprisms are investigated through combined nanometer-resolved electron energy-loss spectroscopy (EELS) and cathodoluminescence (CL) measurements. We show that CL only probes the radiative modes, in contrast to EELS, which additionally reveals dark modes. The combination of both techniques on the same particles thus provides complementary information and also demonstrates that although the radiative modes give rise to very similar spatial distributions when probed by EELS or CL, their resonant energies appear to be different. We trace this phenomenon back to plasmon dissipation, which affects in different ways the plasmon signatures probed by these techniques. Our experiments are in agreement with electromagnetic numerical simulations and can be further interpreted within the framework of a quasistatic analytical model. We therefore demonstrate that CL and EELS are closely related to optical scattering and extinction, respectively, with the addition of nanometer spatial resolution.

Engineering the emission of light from a scanning tunneling microscope using the plasmonic modes of a nanoparticle

“…It is these electric near-field distributions that will be used in one of the approaches proposed below to predict the intensity and angular distribution of the emitted light as a function of the tip excitation position on the NP. Due to the small NP size, we may restrict ourselves to the dipolar resonances since higher-order multipole resonances [42][43][44] are comparatively much less pronounced, and occur above 2.4 eV according to our calculations.…”

“…2(e)]. The nanotriangle supports four basic dipolar excitations: a vertical dipole perpendicular to the substrate, and three degenerate in-plane dipolar modes [42,43], which can be expressed as p x =ê x p || , and…”

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

“…This operation mode provides very accurate simultaneous spatial and spectral information, giving clear correlation between light emission and the position of its excitation, a key to relate optical properties to other local properties as morphology, composition, strain, etc. Indeed, CL techniques have been successfully applied to gain understanding of different systems, including III-V heterostructures [25, 40, 44 , 45 ,46 , 47 ,35, 48 ,49 , 50 , 51 ], diamond [ 52 ,53 , 54 ], plasmonics nanostructures [55,56,57,58] among others.…”

The role of transition radiation in cathodoluminescence imaging and spectroscopy of thin-foils

“…Cathodoluminescence (CL) in the electron microscope is a powerful technique for probing radiative transitions in dielectrics [1], plasmons [2][3], defect properties [4][5][6], strain [7] and carrier lifetime [8][9][10] at high spatial resolution. CL is typically implemented in a scanning electron microscope (SEM), but recently there has been renewed interest in its application as a transmission electron microscope (TEM) technique.…”

“…There are several reasons for this. The first is that CL can be combined with electron energy loss spectroscopy (EELS) in the TEM, which measures both radiative and non-radiative energy loss events and is therefore complementary to CL [2]. Advances in monochromation have also enabled the detection of the EELS signal at deep infra-red wavelengths [11][12].…”