Beam damage of single semiconductor nanowires during X-ray nanobeam diffraction experiments

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Nanoprobe X-ray diffraction (nXRD) is crucial for analyzing individual semiconductor nanowires.
• High X-ray doses and prolonged exposure under ambient conditions can cause radiation damage.
• Understanding radiation damage mechanisms is essential for accurate nanowire characterization.

Purpose of the Study:

• To investigate the origin of radiation damage in semiconductor nanowires during nXRD experiments.
• To compare the effects of nXRD under ambient conditions versus a helium atmosphere.
• To identify strategies for minimizing radiation damage in nanowire analysis.

Main Methods:

• Utilized nanoprobe X-ray diffraction (nXRD) on individual GaAs/In0.2Ga0.8As/GaAs core-shell nanowires.
• Performed experiments at the P08 beamline (PETRA III) using 9 keV X-rays and a photon flux of 10^10 s^-1.
• Employed reciprocal-space mapping, cathodoluminescence spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy.

Main Results:

• Nanowires exposed under ambient conditions exhibited significant optical and morphological damage.
• Exposure under helium atmosphere substantially reduced the observed radiation damage.
• Damage was primarily attributed to X-ray-induced ozone reactions leading to oxidation.

Conclusions:

• Performing nXRD under a helium atmosphere effectively mitigates radiation damage in semiconductor nanowires.
• X-ray-induced oxidation is the main cause of damage under ambient conditions.
• Helium atmosphere preserves nanowire integrity, enabling more reliable structural analysis.