Structural phase transition and bandgap control through mechanical deformation in layered semiconductors 1T-ZrX2 (X = S, Se)

Edoardo Martino; David Santos-Cottin; Florian Le Mardele; Konstantin Semeniuk; Michele Pizzochero; Kristians Cernevics; Benoit Baptiste; Ludovic Delbes; Stefan Klotz; Francesco Capitani; Helmuth Berger; Oleg V. Yazyev; Ana Akrap

arXiv · 2006.07141

Structural phase transition and bandgap control through mechanical deformation in layered semiconductors 1T-ZrX2 (X = S, Se)

Edoardo Martino·David Santos-Cottin·Florian Le Mardele·Konstantin Semeniuk·Michele Pizzochero·Kristians Cernevics·Benoit Baptiste·Ludovic Delbes·Stefan Klotz·Francesco Capitani·Helmuth Berger·Oleg V. Yazyev·Ana Akrap

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Abstract

Applying elastic deformation can tune a material physical properties locally and reversibly. Spatially modulated lattice deformation can create a bandgap gradient, favouring photo-generated charge separation and collection in optoelectronic devices. These advantages are hindered by the maximum elastic strain that a material can withstand before breaking. Nanomaterials derived by exfoliating transition metal dichalcogenides TMDs are an ideal playground for elastic deformation, as they can sustain large elastic strains, up to a few percent. However, exfoliable TMDs with highly strain-tunable properties have proven challenging for researchers to identify. We investigated 1T-ZrS2 and 1T-ZrSe2, exfoliable semiconductors with large bandgaps. Under compressive deformation, both TMDs dramatically change their physical properties. 1T-ZrSe2 undergoes a reversible transformation into an exotic three-dimensional lattice, with a semiconductor-to-metal transition. In ZrS2, the irreversible transformation between two different layered structures is accompanied by a sudden 14 % bandgap reduction. These results establish that Zr-based TMDs are an optimal strain-tunable platform for spatially textured bandgaps, with a strong potential for novel optoelectronic devices and light harvesting.

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Edoardo Martino, David Santos-Cottin, Florian Le Mardele, Konstantin Semeniuk, Michele Pizzochero, Kristians Cernevics, Benoit Baptiste, Ludovic Delbes, Stefan Klotz, Francesco Capitani, Helmuth Berger, Oleg V. Yazyev, Ana Akrap. 2020-06-12. Structural phase transition and bandgap control through mechanical deformation in layered semiconductors 1T-ZrX2 (X = S, Se). https://arxiv.org/abs/2006.07141

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