Free-standing In2O3(ZnO)(m) superlattice microplates grown by optical vapor supersaturated precipitation

摘要

Here, we fabricated In2O3(ZnO)(m) (IZO) superlattice microplates with hexagon morphologies by the substrate-free optical vapor supersaturated precipitation. The IZO microplates possessed a superlattice structure with a large m number, i.e., m = 23, consisting of layered alternating stacks of octahedral InO2- as inversion boundaries and layered InZnmOm+1+ as a zig-zag modulated pattern. The Raman peak at 613 cm(-1) confirmed the superlattice of the IZO microplates. The broad asymmetric excitonic photoluminescence (PL) emission with the photon energy of 3.236 eV indicated the heavy doping of indium in the IZO, resulting a redshift of similar to 32 meV from the near-band-edge emission. The unusual negative thermal quenching of PL intensity was also observed. Moreover, the anisotropic electrical properties of the IZO superlattice microplates were manifested, for the first time, where the in-plane conductivity was two orders of magnitude higher than out-plane one. The present work provided new insight into the free-standing IZO superlattice microdevices for future optoelectronic applications.