http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kee, Suk Nahm,Yang, Seung Hyun,Ahn, Sang Hyung 한국화학공학회 2000 Korean Journal of Chemical Engineering Vol.17 No.1
Thick GaN films were grown on sapphire by the direct reaction of metallic Ga and ammonia in a conventional RF induction heated chemical vapor deposition reactor. The crystalline and optical qualities of the thick GaN were evaluated as functions of the distance between sapphire substrate and Ga source and growth temperature. For thick GaN grown at the position of 3.5 cm away from the Ga source, the FWHM for the (0002) peak of X-ray diffraction (XRD) curve was about 684 arcsec. The growth rate of the thick GaN film was about 18 ㎛/h at this growth condition. The correlation between structural and optical properties of thick GaN films suggested that deep level yellow luminescence (YL) had a close relation with (1010) and (1011) planes developed in the growth. It was speculated that the emission of YL is mainly due to the formation of deep gap state in the band gap by Ga vacancy and impurities trapped at the domain boundary with (1010) and (1011) atomic facets.
( Kee Suk Nahm ),( Tae Yun Kim ),( Sang Hyun Lee ) 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.4
Catalytic effect of metal elements was observed in the growth of GaN and Mg-doped GaN micro-crystals. High quality GaN micro-crystals were synthesized by direct reaction of gallium and ammonia using a Ni-mesh catalyst. Mg-doped GaN micro-crystals were also grown by the same reaction scheme in the presence of MgCl₂. The growth rate of GaN micro-crystals markedly increased in the presence of the catalyst. The average grain size of GaN microcrystals synthesized in the presence of Ni and Mg metals was larger than that in the absence of the metals. The characterization of the catalytically grown GaN micro-crystals using transmission electron microscopy and X-ray and/or electron diffraction pattern showed the growth of dislocation free hexagonal GaN micro-crystals. Photoluminescence (PL) and Catholuminescence (CL) measurements also showed the growth of good quality n- and p-type GaN microcrystals using Ni catalyst
Growth and TEM Characterization of GaN Microcrystals Using a Ni Catalyst
SangHyunLee,KeeSukNahm,KwangChulKim,SangHyunAhn,Eun-KyungSuh,MoonHiHong 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.41 No.1
High-quality GaN microcrystals were grown by direct reaction of gallium and ammonia using a Nimesh catalyst. The catalytic activity markably increased the growth yield of the GaN microcrystals. The average grain size of the GaN microcrystals synthesized in the presence of the Ni catalyst was larger than of the microcrystals synthesized that in the absence of the catalyst. It was thought that the Ni-mesh catalyst accelerated the decomposition of NH3 gas into chemically active nitrogen atom while it reduced the activation energy for the reaction of gallium with NH3. The characterization of the catalytically grown GaN microcrystals using transmission electron microscopy and X-ray and/or electron diraction patterns showed that the hexagonally shaped GaN rods with their c-axis along the length of the single crystal were dislocation free. The growth mechanism of GaN micro-crystals is discussed based on the experimental observation.