Ink-jet printing and drop-casting deposition of 2H-phase SnSe2and WSe2nanoflake assemblies for thermoelectric applications

B Patil; C Bernini; D Marré; L Pellegrino; I Pallecchi

doi:10.1088/1361-6528/ac2f26

Ink-jet printing and drop-casting deposition of 2H-phase SnSe₂and WSe₂nanoflake assemblies for thermoelectric applications

Nanotechnology. 2021 Oct 29;33(3). doi: 10.1088/1361-6528/ac2f26.

Authors

B Patil¹, C Bernini¹, D Marré^{1

2}, L Pellegrino¹, I Pallecchi¹

Affiliations

¹ CNR-SPIN, Corso Perrone 24, 16152 Genova, Italy.
² Università di Genova, Dipartimento di Fisica, Via Dodecaneso 33, 16146 Genova, Italy.

PMID: 34638111
DOI: 10.1088/1361-6528/ac2f26

Abstract

The development of simple, scalable, and cost-effective methods to prepare Van der Waals materials for thermoelectric applications is a timely research field, whose potential and possibilities are still largely unexplored. In this work, we present a systematic study of ink-jet printing and drop-casting deposition of 2H phase SnSe₂and WSe₂nanoflake assemblies, obtained by liquid phase exfoliation, and their characterization in terms of electronic and thermoelectric properties. The choice of optimal annealing temperature and time is crucial for preserving phase purity and stoichiometry and for removing dry residues of ink solvents at inter-flake boundaries, while maximizing the sintering of nanoflakes. An additional pressing is beneficial to improve nanoflake orientation and packing, thus enhancing electric conductivity. In nanoflake assemblies deposited by drop casting and pressed at 1 GPa, we obtained thermoelectric power factors at room temperature up to 2.2 × 10^-4mW m^-1K^-2for SnSe₂and up to 3.0 × 10^-4mW m^-1K^-2for WSe₂.

Keywords: drop-casting; ink-jet printing; thermoelectricity.