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

Thin-film thermoelectrics (TEs) with a thickness of a few microns present an attractive opportunity to power the internet of things (IoT). Here, we propose screen printing as an industry-relevant technology to fabricate TE thin films from colloidal PbSe quantum dots (QDs). Monodisperse 13 nm-sized PbSe QDs with spherical morphology were synthesized through a straightforward heating-up method. The cubic-phase PbSe QDs with homogeneous chemical composition allowed the formulation of a novel ink to fabricate 2 mu m-thick thin films through robust screen printing followed by rapid annealing. A maximum Seebeck coefficient of 561 mu V K-1 was obtained at 143 degrees C and the highest electrical conductivity of 123 S m(-1) was reached at 197 degrees C. Power factor calculations resulted in a maximum value of 2.47 x 10(-5) W m(-1) K-2 at 143 degrees C. To the best of our knowledge, the observed Seebeck coefficient value is the highest reported for TE thin films fabricated by screen printing. Thus, this study highlights that increased Seebeck coefficients can be obtained by using QD building blocks owing to quantum confinement.

Automated summary

This study proposes a method of using screen printing technology to fabricate thin-film thermoelectric films with high Seebeck coefficients. By synthesizing colloidal PbSe quantum dots and rapid annealing, thin films with homogeneous chemical composition and high Seebeck coefficients were obtained. The significance of this study lies in the realization that using quantum dot building blocks can enhance the Seebeck coefficients.