Measuring Device and Material ZT in a Thin-Film Si-Based Thermoelectric Microgenerator

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Thermoelectricity (TE) offers a promising avenue for energy harvesting in small-scale applications and for developing advanced thermal sensors.
• Recent advancements in nanomaterials have led to thermoelectric generators (TEGs) with superior efficiencies compared to traditional bulk materials.

Purpose of the Study:

• To present the thermoelectric characterization of silicon (Si) thin-film based thermocouples for planar micro TEGs.
• To evaluate the performance of these devices across a temperature range of 50 to 350 K.

Main Methods:

• Fabrication of n-type (Phosphorus-doped) and p-type (Boron-doped) Si thin-film thermocouples using selective ion implantation on a 100 nm Si film.
• Experimental determination of thermal conductivity, Seebeck coefficient, and electrical resistivity using in-built heater/sensor probes.
• Refinement of experimental data using finite element modeling (FEM).

Main Results:

• The Si thin films exhibited a thermoelectric figure of merit (zT) of 0.0093 at room temperature, representing a 12% improvement over bulk Si.
• The planar micro TEG demonstrated a figure of merit (ZT) of 0.0046 at room temperature.

Conclusions:

• Silicon thin films are a viable material for thermoelectric applications, offering enhanced performance over bulk counterparts.
• The developed planar micro TEG design shows potential for efficient energy harvesting and thermal sensing.