Synthesis and Study of Oxide Semiconductor Nanoheterostructures in SiO2/Si Track Template

Abstract

In this study, chemical deposition was used to synthesize structures of Ga2O3 -NW/SiO2/Si (NW—nanowire) at 348 K and SnO2 -NW/SiO2/Si at 323 K in track templates SiO2/Si (either nor p-type). The resulting crystalline nanowires were δ-Ga2O3 and orthorhombic SnO2 . Computer modeling of the delta phase of gallium oxide yielded a lattice parameter of a = 9.287 Å, which closely matched the experimental range of 9.83–10.03 Å. The bandgap is indirect with an Eg = 5.5 eV. The photoluminescence spectra of both nanostructures exhibited a complex band when excited by light with λ = 5.16 eV, dominated by luminescence from vacancy-type defects. The current–voltage characteristics of δ-Ga2O3 NW/SiO2/Si-p showed one-way conductivity. This structure could be advantageous in devices where a reverse current is undesirable. The p-n junction with a complex structure was formed. This junction consists of a polycrystalline nanowire base exhibiting n-type conductivity and a monocrystalline Si substrate with p-type conductivity. The I–V characteristics of SnO2 -NW/SiO2/Si suggested near-metallic conductivity due to the presence of metallic tin.