Cathodo-luminescence

Cathodoluminescence microscopy is a scanning electron microscopy technique, contactless and non-destructive, to probe spatial variations of electronic structure of materials.

Cathodoluminescence is based on the emission of light upon electron beam excitation. An incident electron beam, coming from a SEM, hit the sample surface. Interaction of electrons and the matter, following various relaxation processes, can generate electron/hole pairs that can recombine and generate photons.

The intensity and spectral content of the emitted light is a direct measure of important material properties such as bandgap energy, impurity, structural defects, crystallinity, …


Keywords
Luminescence, scanning electron microscopy, electron-hole recombination, radiative recombination


Specifications
The cathodoluminescence microscope is an Attolight system equipped with:

FEG electron gun
3-10keV
Field of view
From 100×100 nm2 up to 150×150 µm2
Sample holder
∅1 inch diameter
Liquid helium cryostat
With temperature controller (5K-300K)
Detectors spectral range
  • 200-1600nm
  • UV visible CCD
  • NIR InGaAs photodiode array
Spectrometer and gratings (groves/mm@blaze)
  • 150@500nm
  • 600@300nm
  • 600@1000nm
  • 320mm focal length

Ascent+ facility
CEA-Leti

Platform Technologies

  • Nano for Quantum Technologies
  • Disruptive Devices
  • Advanced Integration

Key Enabling Technologies

  • Metrology / Characterisation: Physical

Case Study

Users are trying to measure the spatial variation of the emission spectrum of their sample to characterize the material or device properties at the µm scale (from (50nm to 100µm).

They should define if the electron beam can reach the region of interest inside the sample (depth). The expected emission bands should have to be inside the detection range of the equipment. The sample size have to be compatible with the sample holder (<1″).

Typical Applications
Such characterization can be use in the case of III-V nano and/or stack materials characterization, light emitting diodes and other optoelectronic devices

Publications
[DOI: 10.1117/12.2544350]
[DOI: 10.1002/pssb.201900579]
[DOI: 10.1063/1.5027163]
[DOI: 10.1364/OE.25.005488]

Key Enabling Capability

Metrology / Characterisation

Platform Technology

Advanced Integration, Disruptive Devices, Nano for Quantum Technologies

Facility

CEA-Leti