High- 2D SbO Made Using a Substrate-Independent and Low-Temperature Liquid-Metal-Based Process.

High dielectric constant (high-) ultrathin films are required as insulating gate materials. The well-known high dielectrics, including HfO, ZrO, and SrTiO, feature three-dimensional lattice structures and are thus not easily obtained in the form of distinct ultrathin sheets. Therefore, their deposition as ultrathin layers still imposes challenges for electronic industries. Consequently, new high- nanomaterials with in the range of 40 to 100 and a band gap exceeding 4 eV are highly sought after. Antimony oxide nanosheets appear as a potential candidate that could fulfill these characteristics. Here, we report on the stoichiometric cubic polymorph of 2D antimony oxide (SbO) as an ideal high dielectric sheet that can be synthesized a low-temperature, substrate-independent, and silicon-industry-compatible liquid metal synthesis technique. A bismuth-antimony alloy was produced during the growth process. Preferential oxidation caused the surface of the melt to be dominated by α-SbO. This ultrathin α-SbO was then deposited onto desired surfaces a liquid metal print transfer. A tunable sheet thickness between ∼1.5 and ∼3 nm was achieved, while the lateral dimensions were within the millimeter range. The obtained α-SbO exhibited high crystallinity and a wide band gap of ∼4.4 eV. The relative permittivity assessment revealed a maximum of 84, while a breakdown electric field of ∼10 MV/cm was observed. The isolated 2D α-SbO nanosheets were utilized in top-gated field-effect transistors that featured low leakage currents, highlighting that the obtained material is a promising gate oxide for conventional and van der Waals heterostructure-based electronics.