Enhanced Thermoelectric Performance of InSb by Regulating the Carrier Concentration Combined With Resonant Level...

Area of Science:

• Materials Science
• Solid State Physics
• Energy Conversion

Background:

• Indium antimonide (InSb) semiconductors offer potential for medium-temperature thermoelectric devices due to their favorable properties like non-toxicity and stability.
• Challenges in optimizing InSb's electrical properties stem from its single conduction band, small effective mass, and narrow carrier transport range.

Purpose of the Study:

• To enhance the thermoelectric performance of InSb through tin (Sn) doping.
• To investigate the impact of Sn-doping on the electrical and thermal transport properties of InSb.

Main Methods:

• Sn-doping was employed to introduce resonant levels near the Fermi level and optimize carrier concentration in InSb.
• Thermoelectric properties, including power factor and thermal conductivity, were measured.
• Thermoelectric device performance was evaluated.

Main Results:

• Sn-doping significantly improved the electrical conductivity and maintained a high Seebeck coefficient in InSb, resulting in a power factor of ~5.60 mW m^-1 K^-2.
• A peak zT value of 0.80 at 723 K was achieved for InSn_0.00125Sb, a 67% increase compared to intrinsic InSb, due to enhanced power factor and reduced thermal conductivity.
• An InSb-based module demonstrated an open-circuit voltage of 94 mV and output power of 2885 µW under a 320 K temperature difference.

Conclusions:

• Sn-doping is an effective strategy to optimize the thermoelectric performance of InSb-based materials.
• The enhanced InSb exhibits significant potential for practical thermoelectric energy conversion applications, including solar-thermoelectric devices.