Synthesis of two‐dimensional nonlayered α‐Nb₂O₅ nanosheets by the growth promoter of sulfur and alkali halides

Niobium‐based oxides with wide bandgap and high dielectric constant show great potential in the applications of electronic and optoelectronic devices. Herein, the quasi van der Waals epitaxial growth of two‐dimensional (2D) α‐Nb2O5 nanosheets were reported, in which the growth promoter of sulfur and alkali halides have been utilized to catalyze the ultrathin 2D growth. The relatively low Gibbs free energy of α‐Nb2O5 nanosheets could drive the ultrathin growth down to 30 nm on the c‐Al2O3 substrate by the transformation of T‐Nb2O5 powder sources without any doping effects, demonstrating that the diverse α‐Nb2O5 nanostructure morphologies. The as‐grown α‐Nb2O5 nanosheets were characterized with high crystalline quality and specific dominated growth plane indicating the uniform dielectric properties. The metal‐insulator‐metal (MIM) capacitor has confirmed the α‐Nb2O5 nanosheet with a high dielectric constant over 40. Our dual promoters’ growth design strategy provides a universal synthesis method for the 2D nonlayered dielectric materials.This article is protected by copyright. All rights reserved.