Preparation And Luminescence Properties Of Aluminum Nitride Single Crystal Nanowires

Al N has a large direct band gap in the III-nitride semiconductor and is about 6.2 e V at room temperature,making it an important blue and ultraviolet luminescent material.Al N materials also have excellent thermal conductivity,high resistivity,large breakdown field,and small dielectric constant.They have great potential in high temperature,high frequency and high power electronic devices.One-dimensional nanomaterials have unique electrical,thermal and mechanical properties,making Al N nanomaterials have broader application prospects.In recent years,the application of Al N nanomaterials in field emission,photodetectors,and deep ultraviolet LEDs has attracted much attention.At present,the existing methods for growing Al N nanowires are difficult to combine with high efficiency,low cost,simple operation,controllable preparation,and high crystal quality.Therefore,the preparation method of high quality Al N nanowires is still a research hotspot.In this paper,the optimized vapor phase epitaxy method was used to prepare Al N nanowires with small diameter and uniform controllability.we only use N2 and Al vapor as precursors to grow single crystal h-Al N on sapphire(0001)surface.The morphology of Al N nanowires was optimized by adjusting parameters such as growth temperature,V/III ratio,growth pressure,and holding time.Scanning electron microscopy(SEM),X-ray diffraction(XRD)and high resolution transmission electron microscopy(TEM)were used to characterize the crystal structure and surface morphology of Al N nanowires.Selected area electron diffraction(SAED)and X-ray diffraction(XRD)shows that the Al N nanowires are single crystals with a hexagonal symmetry wurtzite structure.The nanowires have a uniform diameter distribution with a diameter of about 50 nm and a aspect ratio of 1000.Nanowires are grown according to the VS and VLS mechanisms.The change of parameters will have a great influence on the crystal structure of nanowires.Finally,we studied the optical properties of Al N nanowires,and tested Raman,photoluminescence(PL)and transmission spectra,respectively,and analyzed the stress and defect luminescence in nanowires.