A high resolution ionoluminescence study of defect creation and interaction

Area of Science:

• Materials Science
• Solid-State Physics
• Optical Spectroscopy

Background:

• Alkali halides like NaCl are susceptible to defect formation under ionizing radiation.
• Defect recombination in these materials can result in visible light emission (color-centers).
• Helium ion microscopy offers high-resolution imaging and analysis capabilities.

Purpose of the Study:

• To investigate the ionoluminescence properties of sodium chloride (NaCl) using helium ion microscopy.
• To characterize the emitted light spectra and identify defect-related emission peaks.
• To explore the influence of beam scanning parameters on defect creation dynamics.

Main Methods:

• Utilized a 35 keV, sub-nanometer He(+) ion beam for excitation.
• Employed helium ion microscopy to generate and detect ionoluminescence.
• Analyzed spectral data to identify emission peaks and their energies.
• Varied beam current and pixel spacing to study defect dynamics.

Main Results:

• Observed broad ionoluminescence peaks in NaCl at 2.46 eV and 3.05 eV.
• Demonstrated that ionoluminescence is associated with the formation and recombination of crystal defects (color-centers).
• Found that defect creation is dependent on helium ion beam scanning parameters.

Conclusions:

• Helium ion microscopy is effective for studying ionoluminescence and defect formation in NaCl.
• The resolution and detection of ionoluminescence are influenced by both sample characteristics and microscopy settings.
• Understanding these parameters is crucial for optimizing defect analysis and imaging.