Advancing Thermoelectric Performance of Bi₂Te₃ below 400 K.

Area of Science:

• Materials Science
• Solid State Physics
• Energy Conversion

Background:

• Thermoelectric cooling devices based on Bismuth Telluride (Bi2Te3) alloys are increasingly used.
• Their performance is limited at operational temperatures below 400 Kelvin (K).
• Limited research has addressed improving their thermoelectric performance in this range.

Purpose of the Study:

• To enhance the thermoelectric performance of Bi2Te3-based alloys.
• To optimize performance within the critical operational temperature range (≤400 K).
• To investigate methods for improving the figure of merit (zT).

Main Methods:

• Modulated carrier concentration by reducing Tellurium (Te) content.
• Introduced Lanthanum (La) doping to optimize electrical transport properties.
• Reduced lattice thermal conductivity through material modifications.

Main Results:

• Reduced Te content shifted the peak zT from 400 K to 300 K.
• Achieved substantial thermoelectric performance enhancement at room temperature (≤400 K).
• Elevated the average zT from 0.69 to 0.9 between 300-400 K via La doping.

Conclusions:

• The study successfully enhanced the thermoelectric performance of Bi2Te3 alloys.
• Optimized carrier concentration and reduced thermal conductivity are key to improved efficiency.
• Findings offer significant potential for advancing current thermoelectric cooling device technology.