Energy storage technologies such as lithium-ion batteries (LIBs) incorporate carbon components key to their function. Graphite and carbon binder components in LIB electrodes are engineered to deliver critical electrical and mechanical properties, as are the surface chemistry and morphology of carbon blacks (CBs) in LIBs and catalysts. The challenge of relating surface chemistry to morphology is complicated by the numerous forms of carbon bonding and potential for surface functional groups. Furthermore, materials processing can influence bonding and structure of carbon at multiple length scales, as seen in mechanochemical functionalization of CBs. To understand the nature of carbon surfaces, secondary electron hyperspectral imaging (SEHI) is introduced as a spatially resolved analysis bridging the nano to microscale. The ability to provide novel insights is demonstrated three example applications: observation of nanoscale "satellite" particles of amorphous hydrogenated carbon on graphitic CB particles, differentiation between graphitic and amorphous hydrogenated nano-thickness carbon coatings on particles of lithium iron phosphate, and differentiation between graphitic carbon active material and carbon binder domain in a LIB anode material. SEHI analysis using peak fitting models for graphitic and disordered carbons is developed based on reference materials and standard spectroscopic methods: Raman spectroscopy and X-ray photoelectron spectroscopy.

Electron spectroscopy proves to be a handy tool in material science. Combination of electron spectroscopy and scanning probe microscopy is possible through Scanning Field Emission Microscopy (SFEM), where a metallic probe positioned close to the surface is used as an electron source. However, using this not too much technologically demanding technique, it looks like the compromise between the lateral resolution and spectroscopic clarity must be considered. Here, we demonstrate, using experimental and simulation data, that the spectroscopic information can be understood without the need to grossly deteriorate the potential spatial resolution of the microscope. We prepared a three-section sample with clean W(110), sub-monolayer Cs on W(110) and monolayer of Cs on W(110) on which electron energy loss spectra are obtained via Scanning Probe Energy Loss Spectroscopy (SPELS) measurements. To explain the detected spectra a new model describing SPELS measurements in a SFEM is developed which aids to uncover the origin of spectral features typically detected during experiments. Experimental and simulation data are in a mutual agreement and observed spectral features on different surfaces could be explained. This novel understanding of SPELS can solve the main issue previously related to this technique, and good spatial resolution can be accompanied by the understanding of the measured spectra.

We report the working of a novel detector design based on a Bessel Box (BB) electron energy analyser in a scanning electron microscope (SEM). We demonstrate the application of our detector for elemental identification through Auger electron detection in an SEM environment and its potential as a complementary technique to energy dispersive X-ray (EDX) spectroscopy. We also demonstrate energy-filtered secondary electron imaging of a copper-on-silicon sample using an electron pass energy of 12 eV. Lay Description Advancements in the field of the Scanning Electron Microscopy have been one of the major nanotechnology enablers. A Scanning Electron Microscope (SEM) generates a magnified image of the sample by bombarding it with an electron beam and detecting the electrons that scatter off the surface along with the electrons that are generated in the sample. Conventional detectors such as the Everhart-Thornley detector (ET) or through-the-lens (TTL) detectors, either offer little to no energy analysis (ET) or limited energy filtering capability (e.g the low-pass energy filter in TTL). This information is crucial to interpret the image of the sample under study. What is needed is a smart and compact detector that can detect electrons and furnish energy inside the SEM chamber. Here, we report a novel secondary electron (SE) detector design with energy analysis capability for use in scanning electron microscopes. The detector is based on the design of a Bessel Box (BB) energy analyser. We have designed and experimentally tested it in an SEM environment. The band-pass filter action of the detector enables the BB to be operated at a selected energy and allows a narrow window of energies to be detected for generating energy-filtered images.

The interpretation of images generated by scanning electron microscopes (SEMs) requires quantifiable and well-understood contrast. Furthermore, recent interest in probing samples using low-energy electrons to extract surface information is pushing towards the quantification of relative contrast in secondary-electron (SE) images. The detection and analysis of low-energy SEs remains at the heart of the development of such instruments and techniques. However, state-of-the-art SE detectors in most SEMs, which are largely using in-lens configurations, are mainly designed to favour the collection of primary-induced SEs, and hence fail to provide electron energy information that could be related to the sample composition. Here, we report on the development of a novel SE detector which makes use of the Bessel box (BB) electron energy analyser. We demonstrate a very compact analyser design ((similar to)a volume of 12mm(3)) through simulations and by acquiring an electron spectrum from a sample of graphene on copper. A resolution of 0.3% has been numerically computed and experimentally verified for the BB analyser.

In a Scanning Field-Emission Microscope (SFEM) [1-3] originating from the topografiner technology [4], the tip-surface distance is few nanometers to few tens of nanometers and the electrons impinging on the target are field emitted from the tip. Accordingly, SFEM is not only capable to map the surface micro-topography as done in conventional Scanning Tunnelling Microscopy – but electrons can escape the tip-surface junction and their intensity detected as a function of the surface position (imaging mode). The SFEM operates at very low primary energies (≤100eV) [5], so that the fundamental mechanisms relevant for the generation and emission of Low-Energy Secondary Electrons are poorly understood. Energy analysis of these electrons would provide useful information, essential e.g. for understanding the origin of contrast in imaging. However, such an energy analysis is made technically difficult by the presence of extremely strong ambient electric fields at the site of origin of the electrons. To overcome this limitation, we have designed and implemented a prototype miniature energy analyser, employing a Bessel Box (BB) [6] technology. The compact design of such a BB, mountable in direct proximity of the tip-surface region, could provide a decisive help toward refining the energy analysis of these Low-Energy Secondary Electrons and toward shedding light on the tangled phenomenon of secondary electron emission. Energy enhanced electron detection in SFEM could lead not only to a novel miniaturized spectro-microscopy device but also provide information about fundamental mechanisms of low energy electron scattering and secondary electron production.

We report the design and experimental characterisation of a miniature detector for the scanning electron microscope based on the Bessel Box (BB) electron energy analyser which has a simple cylindrical geometry. We report on the simulation and operation of a prototype BB. The energy resolution of a single BB has been numerically calculated and experimentally characterised to be < 1%. This miniature electron detector is designed to be used close to the sample, alleviating the effects of the ambient electrostatic and magnetic fields.

Advancements in the field of scanning electron microscopy have been one of the major nanotechnology enablers. A scanning electron microscope (SEM) generates a magnified image of the sample by bombarding it with an electron beam and detecting the electrons that scatter off the surface along with the electrons that are generated in the sample [1]. In conventional SEMs, the generated or secondary electrons (SEs) are detected by the widely adopted Everhart-Thornley detector via a positively biased input-grid [2]. However, in doing so, the energy and angular information of the generated electrons are lost. In addition, this detector collects other tertiary electrons that have been generated by the specimen chamber walls by energetically backscattered electrons, thus reducing the signal quality obtained. Preserving the energy and angular information of the emitted SEs is crucial to interpret the SEM image of the sample under study [1]. Thus, a small scale detector is required that can preserve this information and the performance of which is little affected under the influence of ambient electrostatic and magnetic fields inherent to electron microscopes. In this work we propose the use of the lesser known Bessel box (BB) electron energy analyser (EEA) [3].