Epitaxial film growth of strongly correlated LaNiO ₃ on buffered Si and thermal conductivity modulation based on reversible protonation

Abstract Toward a high-efficiency energy harvesting device, such as a thermal transistor, thermal conductivity modulation based on strongly correlated oxides is proposed and explored. High-quality epitaxial film growth of strongly correlated oxides on large-area Si substrates is essential to match industrial needs. In this work, LaNiO 3 thin films are epitaxially grown on buffer-layer-coated Si(001) substrates. Reversible protonation of the LaNiO 3 thin film via ionic liquid gating achieves thermal conductivity modulation in the range of 0.9 to 3.0 W m −1 K −1 and is comparable to that of a prototype laboratory device on a single crystal substrate.