Preparation,Characterization,and High-pressure Physical Properties Of AlN:Ce Hierarchical Nanostructures

Aluminum nitride?AlN?is a hot material in rare earth doped matrix because of its wide band gap,good thermal and chemical stability.Cerium?Ce?,as a rare earth element with 5d shell exposed,has unique and excellent electronic and photoluminescence properties.1.Firstly,in this paper,Ce doped AlN?AlN:Ce?is selected as our research object,and DC arc plasma assisted method is used to synthetize three samples and adjust the photoluminescence color by the reaction gas conditions.2.Secondly,the composition and morphology of samples were characterized by X-ray diffraction?XRD?,scanning electron microscopy?SEM?,energy dispersive spectrometer?EDS?and X-ray photoelectron spectroscopy?XPS?.The Photoluminescence spectra?PL?of the samples were measured.The emission centers of samples 1,2 and 3 were at 625 nm,520 nm and 475 nm,respectively.The effects of oxygen impurities on the photoluminescence properties of AlN:Ce hierarchical nanostructures were investigated.3.Analysis of physical properties of AlN:Ce under high pressure was investigated by changing material structure and crystal environment of Ce ion under high pressure.High pressure X-ray diffraction?AXRD?and high pressure photoluminescence spectroscopy were carried on red sample 1 and blue sample2.The effects of oxygen impurities on the stability of the lattice structure and photoluminescence stability under high pressure were discussed.It is found that the irreversible structural transformation from wurtzite structure to rock salt structure takes place under the pressure of 6.8 GPa and 18.09 GPa for red light sample 1 and blue light sample 2 under high pressure,respectively.The elastic modulus of wurtzite is B₀=293.75±28.60 GPa and B₀=277.65±3.5 GPa of sample1and 3.The emission center of sample 1 shows a blue shifted and the intensity of luminescence decreases.The emission center of sample 3 is relatively stable under high pressure.The results show that AlN:Ce hierarchical nanostructures have potential applications in the field of optoelectronic devices.The involvement of oxygen impurities makes AlN:Ce hierarchical nanostructures and photoluminescence stabler under high temperature or high pressure.In the future,AlN:Ce hierarchical nanostructures may play an important role in the fields of high pressure blue fluorescent indicator materials and deep sea luminescent materials.