On the Edge: In situ Kelvin probe AFM on InP nanowire arrays.

Area of Science:

• Surface physics
• Nanotechnology
• Materials Science

Background:

• Nanostructured electronic devices, like solar cells, heavily rely on surface physics.
• Semiconductor nanowires offer excellent light absorption and material flexibility for advanced solar cells.
• The unique geometry of nanowires makes their surfaces critical yet challenging to study.

Purpose of the Study:

• To demonstrate a high-resolution, non-destructive atomic force microscopy (AFM) technique for in situ characterization of nanowires.
• To enable direct measurement of nanowires within an array while on their growth substrate.
• To provide a method that preserves structures for subsequent analysis and processing.

Main Methods:

• Utilizing Kelvin probe force microscopy (KPFM), an AFM-based technique.
• Employing a cross-sectional approach for enhanced surface sensitivity.
• Performing in situ measurements on nanowires within an array on their growth substrate.

Main Results:

• Demonstrated a high-resolution, non-destructive AFM technique for nanowire characterization.
• Showcased the ability to measure nanowires in situ without compromising subsequent analysis.
• Found cross-sectional KPFM to be more surface-sensitive and less destructive than electron beam-induced current.

Conclusions:

• Cross-sectional KPFM is a valuable tool for comprehensive nanoelectronic surface characterization.
• The in situ AFM approach ensures measurement integrity and relevance for nanowire devices.
• This technique facilitates rapid and detailed analysis of critical nanowire surfaces in solar cells.