Structural and Luminescence Properties of Ga₂O₃:Zn Micro‐ and Nanostructures

Abstract

High quality Zn‐doped monoclinic gallium oxide micro‐ and nanostructures are obtained by a thermal treatment based on vapor–solid (VS) growth mechanism. Nanowires and ribbons are formed, the latter being the more abundant. The microstructural features are assessed by micro‐Raman and transmission electron microscopy revealing their crystal structure properties, such as the [‐110] growth direction for ribbons and being single crystals. In particular, a strong‐scattered light polarization dependence is reflected in the detected Raman modes. Luminescence of both Zn doped and undoped Ga2O3 samples is thoroughly studied by several techniques, exciting light with electrons or photons. Cathodoluminescence (CL) at a wide temperature range reveals that a band centered at around 2.7 eV, assigned to Zn doping in monoclinic Ga2O3, is thermally activated at temperatures above 200 K and dominates at room temperature. Besides, the characteristic bands at 3.4 and 3.0 eV of undoped Ga2O3 are obtained as well but with less relative intensity. Photoluminescence (PL) analysis at room temperature shows a similar set of bands, but slightly redshifted with respect to CL. Their relative intensities are strongly dependent on the excitation conditions and their time decays are studied by time‐resolved PL (TRPL).

Structural and optoelectronic characteristics of β-Ga2O3 epitaxial films with Zn alloying and subsequent oxygen annealing

“…34 Till now, there have been few studies on single-phase Ga 2 O 3 :Zn materials with high Zn content, and most of the reported components are less than 4%. 32,35…”

Doping of β‐Ga2O3 Layers by Zn Using Halide Vapor‐Phase Epitaxy Process

“…[25] In the case of β-Ga 2 O 3 films deposited by pulsed laser deposition, Zn doping caused reduction of electron concentration and a relative increase in the blue luminescence at %455 nm (%2.7 eV), which is similar to the emission band at 2.7 eV observed in monoclinic Ga 2 O 3 nanostructures obtained by vapor-solid growth mechanism. [26,27] A shift of the dominant photoluminescence peak from %2.8 to %2.3 eV was also observed in Ga 2 O 3 nanostructures synthesized by thermal evaporation method. [28] β-Ga 2 O 3 thin films grown by magnetron sputtering have demonstrated a decrease in the bandgap energy with increasing Zn concentration, and improved characteristics for the metal-semiconductor-metal structure photodetectors was explained by decreased oxygen vacancy concentration.…”

“…[26] Lopez et al observed a modification of the photoluminescence in Zn-doped Ga 2 O 3 nanostructures and related the band at %2.3 eV to the presence of Zn. [27] Jiang et al reported that PL is shifted to %2.25 eV in Zn-doped Ga 2 O 3 compared with the emission centered at 2.8 eV in the undoped samples. [28] Therefore, it was important to investigate the emission in our β-Ga 2 O 3 layers.…”

Study of NiO-NiMn2O4-Patterned Surfaces Fabricated by a Vapor–Solid Process

“…The samples under study were fabricated following a one-step thermal treatment carried out under a controlled atmosphere and temperature. This synthesis method allows to fabricate micro- and nanostructures of diverse oxides with variable morphology and composition without the requirement of any external catalyst, template, or additional substrates, as previously reported. − …”