Air-Stable n-Type Thermoelectric Materials Enabled by Organic Diradicaloids

Area of Science:

• Materials Science
• Organic Electronics
• Thermoelectrics

Background:

• Air-stable n-type organic thermoelectric materials (OTEs) are crucial but challenging due to the volatility of conventional doped materials.
• Controlling doping efficiency and microstructure in traditional OTEs is difficult with external dopants.

Purpose of the Study:

• To design and synthesize novel, air-stable, single-component n-type organic thermoelectric materials.
• To investigate the thermoelectric properties and air stability of diradicaloid-based materials.

Main Methods:

• Synthesis of diradicaloid compounds 2DQQT-S and 2DQQT-Se.
• Fabrication and characterization of pristine films for electrical conductivity and power factor measurements.
• Long-term stability testing under ambient conditions.

Main Results:

• The diradicaloids 2DQQT-S and 2DQQT-Se function as neutral, single-component organic conductors with excellent air stability.
• A pristine film of 2DQQT-Se achieved an electrical conductivity of 0.29 S/cm and a power factor of 1.4 μW/mK².
• No degradation in electrical conductivity was observed for over 260 hours under ambient conditions.

Conclusions:

• Diradicaloids represent a promising new class of air-stable, high-performance n-type organic thermoelectric materials.
• These materials bypass the need for external doping, simplifying fabrication and enhancing stability.
• The findings open new avenues for developing robust organic thermoelectric devices.