Synchronized modulation Kelvin probe force microscopy for surface photovoltage studies in optoelectronic systems

Area of Science:

• Surface science
• Scanning probe microscopy
• Materials characterization

Background:

• Kelvin probe force microscopy (KPFM) is crucial for surface potential analysis.
• KPFM is susceptible to artifacts like drift and thermal effects.
• In-operando measurements require techniques robust against environmental changes.

Purpose of the Study:

• Introduce Synchronized Modulation Kelvin Probe Force Microscopy (SM-KPFM).
• Minimize artifacts in KPFM measurements caused by drift, thermal effects, and probe degradation.
• Enable real-time comparison of surface potentials under external stimuli.

Main Methods:

• Synchronized Modulation Kelvin Probe Force Microscopy (SM-KPFM) synchronizes external stimulus modulation with AFM scanning.
• Synchronized illumination KPFM illuminates the sample during retrace and keeps it dark during trace.
• Demonstrated on silicon photodiodes and MoS2 bilayers on gold.

Main Results:

• Achieved drift-free and accurate surface photovoltage maps.
• Minimized artifacts from environmental factors and probe degradation.
• Provided clearer insights into photovoltaic effects in materials.

Conclusions:

• SM-KPFM is a superior technique for in-operando surface potential measurements.
• The method enables high-fidelity characterization of optoelectronic materials.
• Enhanced understanding of photovoltaic phenomena through artifact reduction.