Giant Tuning of Electronic and Thermoelectric Properties by Epitaxial Strain in p-Type Sr-Doped LaCrO3 Transparent Thin Films
14 September 2021
The impact of epitaxial strain on the structural, electronic, and thermoelectric properties of p-type transparent Sr-doped LaCrO3 thin films has been investigated. For this purpose, high-quality fully strained La0.75Sr0.25CrO3 (LSCO) epitaxial thin films were grown by molecular beam epitaxy on three different (pseudo)cubic (001)-oriented perovskite oxide substrates: LaAlO3, (LaAlO3)0.3(Sr2AlTaO6)0.7, and DyScO3. The lattice mismatch between the LSCO films and the substrates induces in-plane strain ranging from −2.06% (compressive) to +1.75% (tensile).
The electric conductivity can be controlled over 2 orders of magnitude, with σ ranging from ∼0.5 S cm–1 (tensile strain) to ∼35 S cm–1 (compressive strain). Consistently, the Seebeck coefficient S can be finely tuned by a factor of almost 2 from ∼127 μV K–1 (compressive strain) to 208 μV K–1 (tensile strain). Interestingly, we show that the thermoelectric power factor (PF = S2σ) can consequently be tuned by almost 2 orders of magnitude. The compressive strain yields a remarkable enhancement by a factor of 3 for 2% compressive strain with respect to almost relaxed films. These results demonstrate that epitaxial strain is a powerful lever to control the electric properties of LSCO and enhance its thermoelectric properties, which is of high interest for various devices and key applications such as thermal energy harvesters, coolers, transparent conductors, photocatalyzers, and spintronic memories.
Hits: 466
Oxides for new-generation electronics

Giant Tuning of Electronic and Thermoelectric Properties by Epitaxial Strain in p-Type Sr-Doped LaCrO3 Transparent Thin Films

Dong Han, Rahma Moalla, Ignasi Fina, Valentina M. Giordano, Marc d’Esperonnat, Claude Botella, Geneviève Grenet, Régis Debord, Stéphane Pailhès, Guillaume Saint-Girons, and Romain Bachelet*

ACS Appl. Electron. Mater. 2021, 3, 8, 3461–3471 Publication Date:July 28, 2021

Also at ICMAB

  • Bulk photovoltaic effect in hexagonal LuMnO3 single crystals

    31 December 2021 342 hit(s) Oxides
    When illuminating a non-centrosymmetric material with light of energy higher than the bandgap, a net current appears because the electrons do not see the same electronic environment in one direction and the opposite direction, thus they hold a net momentum. This is the bulk photovoltaic effect (BPE), which depends on the light polarization.
  • Efficient spin pumping into metallic SrVO3 epitaxial films

    21 December 2021 300 hit(s) Oxides
    Spin-charge conversion requires materials with a large spin-orbit coupling, which is typically obtained in heavy metal (Pt, etc.) ions. Here we demonstrate spin pumping across interfaces between metallic SrVO3, where V is a 3d1 ion, epitaxial thin films and ferromagnetic Ni80Fe20.
  • Direct and Converse Flexoelectricity in Two-Dimensional Materials

    10 December 2021 343 hit(s) Oxides
    Building on recent developments in electronic-structure methods, we define and calculate the flexoelectric response of two-dimensional (2D) materials fully from first principles. In particular, we show that the open-circuit voltage response to a flexural deformation is a fundamental linear-response property of the crystal that can be calculated within the primitive unit cell of the flat configuration.
  • Determination of the Crystal Structures in the A-Site-Ordered YBaMn2O6 Perovskite

    03 December 2021 335 hit(s) Oxides
    We present a complete structural study of the successive phase transitions observed in the YBaMn2O6 compound with the layered ordering of cations on the perovskite A-site. We have combined synchrotron radiation X-ray powder diffraction and symmetry-adapted mode analysis to describe the distorted structures as pseudosymmetric with respect to the parent tetragonal structure.
  • High-Temperature Synthesis and Dielectric Properties of LaTaON2

    30 November 2021 363 hit(s) Oxides
    The development of new synthetic methodologies of perovskite oxynitrides is challenging but necessary for the search of new compounds and the investigation of new properties. Here, we report a new method of preparation of the perovskite LaTaON2 that has been investigated as a pigment and photocatalyst for water splitting.

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.