Preparation And Optical Properties Of Aluminum Gallium Nitride Materials

Semiconductor Nanomaterials are the most important part in today’s material researchs, and its superior characteristics determine its huge development potential. Ⅲ-Ⅴ compound materials that can represent the third-generation semiconductor materials have a direct band gap, high electron mobility and high thermal conductivity, stable physical and chemical properties, which make them a research hotspot in the world. The band gap of AlxGa1-xN as of Ⅲ-Ⅴ compound semiconductors can be in the range of3.4eV (GaN) to6.2eV (AlN) and be continuously adjustable, and their cutoff wavelength can cover200nm-365nm wavelength range, and then is an ideal material to prepare ultraviolet light-emitting diodes (LED) and UV detector.In the base of the two-step method of the sol-gel method and high temperature ammoniation method, gallium nitrate was selected as the gallium source, aluminum nitrate and aluminum chloride as the aluminum source, ammonia as nitrogen, citric acid as complexing agent, the film samples were prepared by adding the appropriate amount of catalyst and changing experimental conditions. The composition, structure and surface morphology of the as-prepared samples were analyzed by XRD, SEM and EDS, and their photoluminescence and optical properties was test with the PL spectrum and spectral ellipsometry, and then its electrical characteristics were measured with HaLL analytical instrument. The results show that GaN, AlN, AlxGa1-xN(0≤x≤1) films and GaN nanorods are prepared.Using first-principles density functional theory, AlxGa1-xN (x=0.5) models were built with the CASTEP software package, which structural models have been analyzed, and the effect of monatomic defects on the optical characteristics and electronic structures have been calculated when its band structure and density of electronic states have been studied, and the change rule of their optical-electrical properties were searched with x, which founds that the result is consistence with the experimental data and proves that the performance of as-prepared materials is reliable.