High Seebeck Coefficient from Screen-Printed Colloidal PbSe Nanocrystals Thin Film

Area of Science:

• Materials Science
• Nanotechnology
• Energy Conversion

Background:

• Thin-film thermoelectrics (TEs) are crucial for powering the Internet of Things (IoT).
• Screen printing offers an industry-relevant method for fabricating thin-film TEs.
• Colloidal quantum dots (QDs) present novel building blocks for thermoelectric materials.

Purpose of the Study:

• To develop a screen-printing method for fabricating lead selenide (PbSe) quantum dot (QD) based thin-film thermoelectrics.
• To investigate the thermoelectric properties of screen-printed PbSe QD thin films.
• To achieve high Seebeck coefficients in thin-film thermoelectric devices.

Main Methods:

• Synthesis of monodisperse 13 nm PbSe QDs with spherical morphology via a heating-up method.
• Formulation of a novel ink using cubic-phase PbSe QDs for screen printing.
• Fabrication of 2 μm-thick thin films using screen printing followed by rapid annealing.

Main Results:

• Achieved a maximum Seebeck coefficient of 561 μV K^-1 at 143 °C.
• Obtained a highest electrical conductivity of 123 S m^-1 at 197 °C.
• Calculated a maximum power factor of 2.47 × 10^-5 W m^-1 K^-2 at 143 °C, the highest reported for screen-printed TE thin films.

Conclusions:

• Screen printing is a viable technology for fabricating high-performance thermoelectric thin films from PbSe QDs.
• Quantum confinement in QD building blocks significantly enhances Seebeck coefficients.
• This approach offers a promising route for developing efficient thermoelectric power sources for IoT applications.