Tuning Optimum Temperature Range of Bi₂ Te₃ -Based Thermoelectric Materials by Defect Engineering

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Bismuth telluride (Bi₂Te₃)-based materials are crucial for room-temperature thermoelectric (TE) refrigeration.
• These materials also show potential for power generation using low-to-medium temperature heat sources.
• Optimizing TE properties across different temperature ranges is key for diverse applications.

Purpose of the Study:

• To review defect engineering strategies for enhancing Bi₂Te₃-based thermoelectric materials.
• To explore how manipulating point defects optimizes TE properties at various temperatures.
• To provide guidance for improving Bi₂Te₃ TE performance through defect control.

Main Methods:

• Focus on defect engineering as a primary method for property optimization.
• Utilize a two-band model for theoretical calculations.
• Analyze experimental paradigms for n-type and p-type Bi₂Te₃ materials (ingots and polycrystals).

Main Results:

• Defect engineering effectively tunes carrier concentration and band gap in Bi₂Te₃.
• Optimized carrier concentration and band gap lead to improved TE properties at different temperatures.
• Specific defect engineering approaches are discussed for n-type and p-type Bi₂Te₃.

Conclusions:

• Defect engineering is a vital strategy for tailoring Bi₂Te₃ thermoelectric performance.
• Controlling point defects allows for optimization across a spectrum of operating temperatures.
• This review offers a framework for advancing Bi₂Te₃-based thermoelectric devices.