Theoretical Calculation And Preparation Of One-Dimensional In_xGa_1-xN Nanostructures

As an important member of III group nitride semiconductor, InGaN ternary alloy has the adjustable band gap and excellent photoelectric performance. One-dimensional InGaN nanowires have both excellent properties of InGaN alloy and the special effect of one dimensional structure. In the development of optoelectronic devices, InGaN nanowires can improve the luminous performance and has important practical value.In this paper, the first-principle calculation are carried out for InxGa1-xN (x=0,0.04, 0.08,0.125,0.25,0.75,0.875,0.92,0.96,1) nanowires in CASTEP code of Material Studio software. After establishing and optimizing the nanowires model, the structure stability, hand structure, density of states and optical properties of InxGa1-xN nanowires are calculated and analyzed. The results show that it is more stable with replacing inner atoms in the model of one-dimensional InxGa1-xN. One-dimensional GaN, InN and InxGa1-xN are all direct band gap semiconductors. Owing to the small size effect, the band gap of one-dimensional nanomaterials is greater than the bulk materials. With the increase of indium components, the band gap of one-dimensional InGaN alloy decreased, and the dielectric constant and the intensity of absorption peak are increased, at the same time,the optical loss peak gradually moving towards to high energy and the loss increased. The optical absorption of one-dimensional InxGa1-xN is in the range of 100nm to 1000nm, covering a broad spectral range from infrared to ultraviolet.In the experiment, the one-dimension GaN, InN and InGaN are prepared with the sol-gel method and magnetron sputtering method combined with high temperature ammoniation. According to characterization and analysis, the results show that one-dimensional GaN, InN, and Ga-rich InGaN nanostructures grow with nickel and gold as catalysts by the sol-gel method. By magnetron sputtering method, the dense and homogeneous In-rich InGaN nanowires can be acquired with the catalyst of Co. It has a great impact on indium components and crystallinity of InGaN by adjusting the temperature and time of ammoniation. With the increase of indium components, the crystallinity of InGaN alloy decreases and the photoluminescence peak red shifts.