Solution-processed negative gauge factor PtSe2 strain sensors

Cansu Ilhan; Eoin Caffrey; Shixin Liu; Jose Munuera; Zdeněk Sofer; Iva Plutnarová; Michael A. Morris; Jonathan N. Coleman; Tian Carey

doi:10.1039/D5NR01217A

Solution-processed negative gauge factor PtSe₂ strain sensors†

Cansu Ilhan,^a Eoin Caffrey,

^b Shixin Liu,^b Jose Munuera,

^bc Zdeněk Sofer,

^d Iva Plutnarová,

^d Michael A. Morris,

^a Jonathan N. Coleman

*^b and Tian Carey

*^b

Author affiliations

* Corresponding authors

^a School of Chemistry, CRANN & AMBER Research Centres, Trinity College Dublin, Dublin 2, Ireland

^b School of Physics, CRANN & AMBER Research Centres, Trinity College Dublin, Dublin 2, Ireland
E-mail: careyti@tcd.ie, colemaj@tcd.ie

^c Instituto de Ciencia y Tecnología del Carbono INCAR-CSIC, C/Francisco Pintado Fe 26, Oviedo 33011, Spain

^d Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, Prague 6, 166 28, Czech Republic

Abstract

We undertake electrochemical exfoliation of a 2D semiconductor platinum diselenide, PtSe₂ and investigate the piezoresistance response of a solution-processed network. Due to the large PtSe₂ aspect ratios, exceeding 300, we achieve conformal flake-to-flake junctions and good inter-flake electrical coupling. Our measured piezoresistive gauge factor is negative (−5.45), consistent with the intrinsic negative gauge factor of PtSe₂. This negative network gauge factor implies that strain is transferred from the substrate to the nanosheets. However, detailed modelling shows that the strain transferred to the nanosheets is much smaller than the applied strain, showing that conformal junctions do not necessarily lead to good mechanical coupling between nanosheets. Our model implies that this gauge factor is consistent with a strain transfer efficiency of 8.5%. Our strain sensor also demonstrated a cyclic response for over 1000 cycles, enabling the sensor to be used in future flexible optoelectronics applications.

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Article information

DOI: https://doi.org/10.1039/D5NR01217A
Article type: Communication
Submitted: 24 Mar 2025
Accepted: 07 Jul 2025
First published: 08 Jul 2025
This article is Open Access

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Nanoscale, 2025, Advance Article

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Solution-processed negative gauge factor PtSe₂ strain sensors

C. Ilhan, E. Caffrey, S. Liu, J. Munuera, Z. Sofer, I. Plutnarová, M. A. Morris, J. N. Coleman and T. Carey, Nanoscale, 2025, Advance Article , DOI: 10.1039/D5NR01217A

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