Synthesis of freestanding single-crystal perovskite films and heterostructures by etching of sacrificial water-soluble layers.
The ability to create and manipulate materials in two-dimensional (2D) form has repeatedly had transformative impact on science and technology. In parallel with the exfoliation and stacking of intrinsically layered crystals, atomic-scale thin film growth of complex materials has enabled the creation of artificial 2D heterostructures with novel functionality and emergent phenomena, as seen in perovskite heterostructures. However, separation of these layers from the growth substrate has proved challenging, limiting the manipulation capabilities of these heterostructures with respect to exfoliated materials. Here we present a general method to create freestanding perovskite membranes. The key is the epitaxial growth of water-soluble Sr3Al2O6on perovskite substrates, followed by in situ growth of films and heterostructures. Millimetre-size single-crystalline membranes are produced by etching the Sr3Al2O6layer in water, providing the opportunity to transfer them to arbitrary substrates and integrate them with heterostructures of semiconductors and layered compounds.
Department of Physics, Stanford University, Stanford, California 94305, USA.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Di
D
Lu
School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, USA.
David J
DJ
Baek
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.|Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Seung Sae
SS
Hong
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.|Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA.
Lena F
LF
Kourkoutis
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Yasuyuki
Y
Hikita
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.|Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Harold Y
HY
Hwang