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In recent years , the wide band gap semiconductor material GaN broad application prospects in the short wavelength light emitting devices , photodetectors pieces , as well as anti-radiation , high-frequency and high-power electronic devices of concern , the growth of high quality GaN materials is the research and development of GaN basic prerequisite based devices . Most of the production of GaN-based devices on sapphire . However, since the sapphire substrate itself insulated and hardness, and the complex process of the devices , the production cost is high , and because of its poor thermal conductivity , is not conducive to the production of high-power devices , a silicon substrate can make up for these deficiencies . Therefore , to carry out significant epitaxial growth of GaN thin films on Si substrate . In the system , the paper summarizes the history of the home and abroad GaN Materials and Devices process , the status quo based on the use of their own design and manufacture MOCVD system silicon epitaxial growth of GaN and characteristics , as well as with catalytic Prepared the GaN nanorods and its growth mechanism . Achieved through a variety of means of testing and theoretical analysis , some initial results : 1 . , Respectively, using a low temperature , high temperature AlN buffer layer growth of GaN films . The high temperature buffer layer , and the thickness of the buffer layer , the V / III as well as the carrier gas composition on the GaN film quality , using 170nm thickness of the high temperature AlN as the buffer layer system had the crystalline quality , a good crack-free GaN films . The catalyst - assisted vapor deposition reaction successfully prepared the GaN nanorods low dimensional structure , the use of XRD , SEM , EDS , TEM , SAED , PL products were to characterize the structure and optical properties . The results show that : the product is a wurtzite - type GaN, nanorods a diameter of 50 to 150 nm , up to several microns , front portion was needle-like . From the kinetics analysis of the nanorod shape characteristics , possible causes .
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