A dark mode in scanning thermal microscopy.

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Thermal Physics

Background:

• Scanning Thermal Microscopy (SThM) requires high lateral spatial resolution, driving the development of smaller probes.
• Miniaturized SThM probes are increasingly sensitive to size effects and heat flux variations.
• Accurate thermal management is crucial to mitigate parasitic phenomena and ensure reliable SThM measurements.

Purpose of the Study:

• To investigate the influence of the optical detection laser on SThM measurements.
• To quantify the bias introduced by laser-induced overheating in thermoresistive SThM probes.
• To propose and validate a novel SThM experimental procedure for accurate thermal flux measurements.

Main Methods:

• Utilized a Scanning Thermal Microscopy (SThM) setup based on atomic force microscopy equipment.
• Employed thermoresistive probes (palladium from Kelvin Nanotechnology) for thermal measurements.
• Developed and implemented a SThM 'dark mode' experimental procedure, avoiding laser illumination.

Main Results:

• Demonstrated significant bias in SThM measurements due to laser-induced overheating of the probe.
• Quantified errors ranging from 14% to 37% in heat flux measurements using the classical laser-on method.
• The SThM 'dark mode' procedure effectively eliminates laser-induced thermal bias.

Conclusions:

• Laser illumination in standard SThM setups introduces substantial errors in heat flux measurements.
• The proposed SThM 'dark mode' offers a metrologically sound approach for accurate thermal characterization.
• This advancement is critical for reliable analysis of sample thermal properties at the nanoscale.