Low-Dimensional Ga₂O₃Nano-Material:Synthesis,Doping And Photoluminescence Properties

Gallium oxide is a wide-band-gap semiconductor material. Now, it is a hot spot to study Ga2O3nanostructures. Ga2O3nanomaterials have many applications in electronic and optoelectronic devices due to their excellent electronic and optical properties, chemical and thermodynamic inertness.In this paper, we developed a VS growth method to synthesis of low-dimensional Ga2O3nanostructures. The products synthesized in different conditions presented different morphologies, which may be related to the partial pressure of oxygen in the surroundings. The photoluminescence (PL) spectra of Ga2O3nanoparticles were measured at room temperature, which indicated that the as-prepared Ga2O3nanoparticles performed a broad blue-green emission band.Then, we synthesized uniform single-crystalline spherical β-Ga2O3particles by a simple method in ambient atmosphere. No pre-treatment, catalyst, substrate, or gas flow was required during the synthesis process. The spherical β-Ga2O3particles performed special optical property, and the PL spectra included a broad blue-green light emission and an interesting red light emission at room temperature, which may be beneficial to application in LED phosphors. Finally, the mechanisms of the growth and the photoluminescence were given by comparing the morphologies and PL spectra of different samples synthesized in different conditions.We also studied the optical properties of the spherical β-Ga2O3particles with different N doping concentrations. It is found that the red light emission was dependent on the content of nitrogen doping by studying the PL spectra of Ga2O3particles doped with N. A proper nitrogen concentration can lead to a relatively strong red light emission. So it is very important to strictly control the post annealing treatment of the products in NH3atmosphere with desired heating temperatures and times.The Ga2O3particles were also prepared with Eu3+and Ge4+doping, respectively. The PL spectra of the products with Eu3+doping showed an additional emission peak centered at615nm expect the blue-green and red light emissions, which were induced by the intrinsic emission of Eu3+(5D0-7F2transition). Furthermore, the intensity of the light emission was affected by the doping conditions. While, the red light emission became weaker of the Ga2O3particles doped with Ge4+, also the morphologies and structures were influenced.Finally, cubic spinel ZnGa2O4was synthesized by solid-state reaction of Ga2O3and ZnO powders. The PL properties of the products were dependent on the molar ratios of Ga2O3and ZnO and the synthesis conditions.