Automated One-Drop Assembly for Facile 2D Film Deposition

The effective application of 2D materials is strongly dependent on the mass production of high-quality large-area 2D thin films. Here, we demonstrate a strategy for the automated manufacturing of high-quality 2D thin films using a modified drop-casting approach. Our approach is simple; by using an automated pipette, a dilute aqueous suspension is dropped onto a substrate heated on a hotplate, and controlled convection by Marangoni flow and liquid removal causes the nanosheets to come together to form a tile-like monolayer film in 1–2 min. Ti0.87O2 nanosheets are utilized as a model system for investigating the control parameters such as concentrations, suction speeds, and substrate temperatures. We perform the automated one-drop assembly of a range of 2D nanosheets (metal oxides, graphene oxide, and hexagonal boron nitride) and successfully fabricate various functional thin films in multilayered, heterostructured, and sub-micrometer-thick forms. Our deposition method enables on-demand large-size (>2 inchϕ) manufacturing of high-quality 2D thin films while reducing the time and sample consumption

Automated One-Drop Assembly for Facile 2D Film Deposition

The effective application of 2D materials is strongly dependent on the mass production of high-quality large-area 2D thin films. Here, we demonstrate a strategy for the automated manufacturing of high-quality 2D thin films using a modified drop-casting approach. Our approach is simple; by using an automated pipette, a dilute aqueous suspension is dropped onto a substrate heated on a hotplate, and controlled convection by Marangoni flow and liquid removal causes the nanosheets to come together to form a tile-like monolayer film in 1–2 min. Ti0.87O2 nanosheets are utilized as a model system for investigating the control parameters such as concentrations, suction speeds, and substrate temperatures. We perform the automated one-drop assembly of a range of 2D nanosheets (metal oxides, graphene oxide, and hexagonal boron nitride) and successfully fabricate various functional thin films in multilayered, heterostructured, and sub-micrometer-thick forms. Our deposition method enables on-demand large-size (>2 inchϕ) manufacturing of high-quality 2D thin films while reducing the time and sample consumption

Automated One-Drop Assembly for Facile 2D Film Deposition

The effective application of 2D materials is strongly dependent on the mass production of high-quality large-area 2D thin films. Here, we demonstrate a strategy for the automated manufacturing of high-quality 2D thin films using a modified drop-casting approach. Our approach is simple; by using an automated pipette, a dilute aqueous suspension is dropped onto a substrate heated on a hotplate, and controlled convection by Marangoni flow and liquid removal causes the nanosheets to come together to form a tile-like monolayer film in 1–2 min. Ti0.87O2 nanosheets are utilized as a model system for investigating the control parameters such as concentrations, suction speeds, and substrate temperatures. We perform the automated one-drop assembly of a range of 2D nanosheets (metal oxides, graphene oxide, and hexagonal boron nitride) and successfully fabricate various functional thin films in multilayered, heterostructured, and sub-micrometer-thick forms. Our deposition method enables on-demand large-size (>2 inchϕ) manufacturing of high-quality 2D thin films while reducing the time and sample consumption

Automated One-Drop Assembly for Facile 2D Film Deposition

The effective application of 2D materials is strongly dependent on the mass production of high-quality large-area 2D thin films. Here, we demonstrate a strategy for the automated manufacturing of high-quality 2D thin films using a modified drop-casting approach. Our approach is simple; by using an automated pipette, a dilute aqueous suspension is dropped onto a substrate heated on a hotplate, and controlled convection by Marangoni flow and liquid removal causes the nanosheets to come together to form a tile-like monolayer film in 1–2 min. Ti0.87O2 nanosheets are utilized as a model system for investigating the control parameters such as concentrations, suction speeds, and substrate temperatures. We perform the automated one-drop assembly of a range of 2D nanosheets (metal oxides, graphene oxide, and hexagonal boron nitride) and successfully fabricate various functional thin films in multilayered, heterostructured, and sub-micrometer-thick forms. Our deposition method enables on-demand large-size (>2 inchϕ) manufacturing of high-quality 2D thin films while reducing the time and sample consumption

Automated One-Drop Assembly for Facile 2D Film Deposition

The effective application of 2D materials is strongly dependent on the mass production of high-quality large-area 2D thin films. Here, we demonstrate a strategy for the automated manufacturing of high-quality 2D thin films using a modified drop-casting approach. Our approach is simple; by using an automated pipette, a dilute aqueous suspension is dropped onto a substrate heated on a hotplate, and controlled convection by Marangoni flow and liquid removal causes the nanosheets to come together to form a tile-like monolayer film in 1–2 min. Ti0.87O2 nanosheets are utilized as a model system for investigating the control parameters such as concentrations, suction speeds, and substrate temperatures. We perform the automated one-drop assembly of a range of 2D nanosheets (metal oxides, graphene oxide, and hexagonal boron nitride) and successfully fabricate various functional thin films in multilayered, heterostructured, and sub-micrometer-thick forms. Our deposition method enables on-demand large-size (>2 inchϕ) manufacturing of high-quality 2D thin films while reducing the time and sample consumption

RbBiNb₂O₇: A New Lead-Free High‑<i>T</i>_c Ferroelectric

RbBiNb₂O₇: A New Lead-Free High‑<i>T</i>_c Ferroelectri

Oriented Film Growth of Ba_1–<i>x</i>Sr_<i>x</i>TiO₃ Dielectrics on Glass Substrates Using 2D Nanosheet Seed Layer

An approach to fabricate Ba_0.5Sr_0.5TiO₃ (BST) films with a preferred orientation on a glass substrate by pulsed laser deposition was developed. To ensure a preferred crystallographic orientation, we utilized a molecularly thin Ca₂Nb₃O₁₀ perovskite nanosheet as a seed layer and successfully fabricated BST films with a nearly perfect (100)-axis orientation. The 100 nm films after annealing at 450 °C in air showed a good dielectric performance (ε_r > 400), which was comparable to the ε_r value of epitaxially grown films with the same thickness. These results indicate that the nanosheet seed layer plays a crucial role in controlled film growth, realizing a nearly intrinsic performance of BST

High Thermal Robustness of Molecularly Thin Perovskite Nanosheets and Implications for Superior Dielectric Properties

A systematic study has been conducted to examine the thermal stability of layer-by-layer assembled films of perovskite-type nanosheets, (Ca₂Nb₃O₁₀^–)_<i>n</i> (<i>n</i> = 1–10), which exhibit superior dielectric and insulating properties. In-plane and out-of-plane X-ray diffraction data as well as observations by atomic force microscopy and transmission electron microscopy indicated the high thermal robustness of the nanosheet films. In a monolayer film with an extremely small thickness of ∼2 nm, the nanosheet was stable up to 800 °C, the temperature above which segregation into CaNb₂O₆ and Ca₂Nb₂O₇ began. The critical temperature moderately decreased as the film thickness, or the number of nanosheet layers, increased, and reached 700 °C for seven- and 10-layer films, which is comparable to the phase transformation temperature for a bulk phase of the protonic layered oxide of HCa₂Nb₃O₁₀·1.5H₂O as a precursor of the nanosheet. This thermal stabilization of perovskite-type nanosheets should be associated with restricted nucleation and crystal growth peculiar to such ultrathin 2D bound systems. The stable high-<i>k</i> dielectric response (ε_r = 210) and highly insulating nature (<i>J</i> < 10^–7 A cm^–2) remained substantially unchanged even after the nanosheet film was annealed up to 600 °C. This study demonstrates the high thermal stability of 2D perovskite-type niobate nanosheets in terms of structure and dielectric properties, which suggests promising potential for future high-<i>k</i> devices operable over a wide temperature range

Atomic Layer Engineering of High‑κ Ferroelectricity in 2D Perovskites

Complex perovskite oxides offer tremendous potential for controlling their rich variety of electronic properties, including high-<i>T</i>_C superconductivity, high-κ ferroelectricity, and quantum magnetism. Atomic-scale control of these intriguing properties in ultrathin perovskites is an important challenge for exploring new physics and device functionality at atomic dimensions. Here, we demonstrate atomic-scale engineering of dielectric responses using two-dimensional (2D) homologous perovskite nanosheets (Ca₂­Na_<i>m</i>–3­Nb_<i>m</i>­O_3<i>m</i>+1; <i>m</i> = 3–6). In this homologous 2D material, the thickness of the perovskite layers can be incrementally controlled by changing <i>m</i>, and such atomic layer engineering enhances the high-κ dielectric response and local ferroelectric instability. The end member (<i>m</i> = 6) attains a high dielectric constant of ∼470, which is the highest among all known dielectrics in the ultrathin region (<10 nm). These results provide a new strategy for achieving high-κ ferroelectrics for use in ultrascaled high-density capacitors and post-graphene technology

2D Perovskite Nanosheets with Thermally-Stable High‑κ Response: A New Platform for High-Temperature Capacitors

We investigated high-temperature dielectric responses of high-κ perovskite nanosheet (Ca₂Nb₃O₁₀), an important material platform for postgraphene technology and ultrascale electronic devices. Through <i>in situ</i> characterizations using conducting atomic force microscopy, we found a robust high-temperature property of Ca₂Nb₃O₁₀ nanosheet even in a monolayer form (∼2 nm). Furthermore, layer-by-layer assembled nanocapacitors retained both size-free high-ε_r characteristic (∼200) and high insulation resistance (∼1 × 10^–7 A/cm²) at high temperatures up to 250 °C. The simultaneous improvement of ε_r and thermal stability in high-κ nanodielectrics is of critical technological importance, and perovskite nanosheet has great potential for a rational design and construction of high-temperature capacitors