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81.
Gu Biao Xu Yin Qin Fu Wen Wang San Sheng Sui Yu Wang Zhan Guo 《Plasma Chemistry and Plasma Processing》2002,22(1):161-176
To heteroepitaxally grow the crystalline cubic-GaN (c-GaN) film on the substrates with large lattice mismatch is basically important for fabricating the blue or ultra-violet laser diodes based on cubic group III nitride materials. We have obtained the crystalline c-GaN film and the heteroepitaxial interface between c-Gan and GaAs(001) substrate by the ECR Plasma-Assisted Metal Organic Chemical Vapor Deposition (PA-MOCVD) under low-pressure and low-temperature (600°C) on a homemade ECR-plasma Semiconductor Processing Device (ESPD). In order to decrease the growth temperature, the ECR plasma source was adopted as the activated nitrogen source, therefore the working pressure of MOCVD was decreased down to the region less than 1 Pa. To eliminate the damages from energetic ions of current plasma source, a Multi-cusp cavity-coupling ECR Plasma source (MEP) was selected to use in our experiment. To decrease the strain and dislocations induced from the large lattice mismatch between c-GaN and GaAs substrate, the plasma pretreatment procedure i.e., the initial growth technique was investigated. The experiment arrangements, the characteristics of plasma and the growth procedure, the characteristics of c-GaN film and interface between c-GaN and GaAs(001), and the roles of ECR plasma are described in this contribution. 相似文献
82.
LIU Ming-fei HU Yong-xing JIANG Yin-zhu GAO Jian-feng WANG Yan-yan MENG Guang-yao 《高等学校化学研究》2007,23(3):258-262
Praseodymium β-diketone chelate, Pr(DPM)3 [DPM=2,2,6,6-tetramethyl-3,5-heptanedionato], was successfully synthesized from the inorganic salt praseodymium chloride and HDPM(2,2,6,6-tetramethyl-3,5-heptane-dione) in an ethanol/aqueous solution followed distillation at low pressure and recrystallization from toluene. The physical and thermal properties of the chelate, including volatility, stability, and thermal decomposition, were investigated by elemental analyses, 1H NMR spectroscopy, XRD, TG/DTG/DTA analysis, infrared spectroscopy, and mass spectroscopy. The chelate with high purity prepared by thes of this study also shows sufficient volatility and stability in inert gases, which could be used as the precursor for metal-organic chemical vapor deposition(MOCVD). 相似文献
83.
以FeCl3和四甲基庚二酮(HDPM)为原料,在醇/水混合溶剂中合成β-二酮金属有机化合物Fe(DPM)3。利用红外吸收光谱、元素分析、原子吸收光谱、差热-热重和质谱分析等技术,分析了Fe(DPM)3的结构、纯度、热稳定性、挥发性以及热分解机理。结果显示,合成的Fe(DPM)3在空气气氛和氮气气氛下均具有良好的挥发性,气化失重率达到98%以上,空气气氛中氧的存在对Fe(DPM)3的气化和分解具有一定的促进作用;质谱分析结果表明:在Fe(DPM)3的分解过程中,首先有一个DPM配体解离,然后在剩余两个DPM配体中先解离出-C(CH3)3基团,随后分裂出剩下的-OCCH2COC(CH3)3基团,最后得到+Fe(DPM)碎片。本文同时以新合成的Fe(DPM)3作为前驱物,采用气溶胶辅助的金属有机化学气相沉积(Aerosol Assisted MOCVD,AA-MOCVD)技术在α-Al2O3衬底上成功沉积制备了α-Fe2O3薄膜。 相似文献
84.
The salt elimination reaction of the transition carbonyl metal-lates [L(CO)nM](Na/K) (M = Cr, Mo, W, Mn, Re, Fe, Co, Ni; L= CO, n5-C5R5, PR3; n= 1-4; R= alkyl, aryl) with the base-stabilized galliumhalides ClaGaR3 -a(Do) (R = H, alkyl, halide; Do = THF, N(CH3)3, NC7H13) or ClaGa[(CH2)3N-R2](R)2 - a yielded almost quantitatively the transition metal-substituted, gallanes [L(CO)nM]aGaR3 - a(Do) and [L(CO)n-M]aGa[(CH2)3NR2](R)2 - a, respectively. Residual halide functionalities in these complexes were selectively replaced by various other groups. The new compounds were characterized by means of elemental analysis, 1H-, 13C-, 31P-NMR, MS, and lR v(CO) data. The single-crystal X-ray structure analysis of trans-(Ph3P)(CO)3Co-Ga[(CH2) 3N(C2H5)2](R)( 6s : R = Cl, 6t : R= CH3) showed s̀(Co-Ga) lengths of 237.78(4) and 249.5(1) pm, respectively. A short s̀(Fe-Ga) contact of 236.18(3) pm was found for (n5-C5H5)(CO)2Fe-Ga-Cl2[N(CH 3)3] ( 5a ). Low-pressure MOCVD experiments were performed to give thin films of analytically pure CoGa alloy. 相似文献
85.
Anthony Birri Graeme Hogarth Elif Subasi 《Journal of organometallic chemistry》2007,692(12):2448-2455
Allyl-palladium dithiocarbamate complexes, [Pd(allyl)(S2CNR2)], have been prepared from the addition of dithiocarbamate salts to [Pd(allyl)(μ-Cl)]2 and TGA and DSC studies have been carried out in order to assess their potential as MOCVD precursors to palladium sulfides. For comparison [(η3-C4H7)Pd(S2PPh2)] and [Pd(S2CNMeR)2] (R = Bu, Hex) have also been prepared and tested as precursors. The unsymmetrical dithiocarbamate complex, [(η3-C3H5)Pd(S2CNMeHex)], which has a melting point of 65 °C was selected as the best single source precursor and thin films of predominantly Pd2.8S were deposited on glass slides. The crystal structures of [(η3-C4H7)Pd(S2CNMe2)], [(η3-C4H7)Pd(S2CNPr2)], [(η3-C4H7)Pd(S2PPh2)] and [Pd(S2CNMeBu)2] are reported. All except [(η3-C4H7)Pd(S2CNPr2)] show weak intermolecular S?H or Pd?H interactions. 相似文献
86.
A 4×4 metal-semiconductor-metal rectangular deep-ultraviolet detector array of Ga2O3 photoconductor with high photo response 下载免费PDF全文
A 4$\times $4 beta-phase gallium oxide ($\beta $-Ga$_{2}$O$_{3}$) deep-ultraviolet (DUV) rectangular 10-fingers interdigital metal-semiconductor-metal (MSM) photodetector array of high photo responsivity is introduced. The Ga$_{2}$O$_{3}$ thin film is prepared through the metalorganic chemical vapor deposition technique, then used to construct the photodetector array via photolithography, lift-off, and ion beam sputtering methods. The one photodetector cell shows dark current of 1.94 pA, photo-to-dark current ratio of 6$\times $10$^{7}$, photo responsivity of 634.15 A$\cdot$W$^{-1}$, specific detectivity of 5.93$\times $10$^{11}$ cm$\cdot$Hz$^{1/2}\cdot$W$^{-1}$ (Jones), external quantum efficiency of 310000%, and linear dynamic region of 108.94 dB, indicating high performances for DUV photo detection. Furthermore, the 16-cell photodetector array displays uniform performances with decent deviation of 19.6% for photo responsivity. 相似文献
87.
88.
New tetranuclear complexes of copper and cobalt have been prepared under ambient conditions from corresponding metal acetates in acetone, using triethanolamine and diethanolamine as the ligands. The complexes have been characterized by infrared spectroscopy, mass spectroscopy, elemental analysis and thermal analysis. The mass spectra of the complexes show that the complexes retain the acetate moiety in their structures. Simultaneous thermogravimetric and differential thermal analysis (TGA–DTA) reveal that the complexes are solids that sublime over the temperature range 50–100 °C, under atmospheric pressure. The TGA–DTA curves reveal that the complexes retain carbon at temperatures as high as 500 °C. The presence of carbon is known to limit the mobility of growth species for oxides, restricting them to nanometersized crystals. Thus, the complexes have potential applications as precursors in the growth of nanostructured metal oxide thin films under specific CVD conditions. Because of their low sublimability, the complexes are prospective candidates as precursors for low‐temperature growth of multilayer oxide thin films where the thickness of individual layers needs to be controlled at nanometer level and for introducing dopants at low concentrations by MOCVD technique. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
89.
Xian Tao Ke‐Cheng Shen Qing‐Yun Tang Meng Feng Jiang‐Tao Fang Yu‐Long Wang Ying‐Zhong Shen 《应用有机金属化学》2012,26(2):67-73
Six organophosphine/phosphite‐stabilized silver(I) N‐hydroxysuccinimide complexes of type [C4H4NO3Ag?Ln] (L = PPh3; n = 1, 2a; n = 2, 2b; L = P(OEt)3; n = 1, 2c; n = 2, 2 d; L = P(OMe)3; n = 1, 2e; n = 2, 2f) were prepared. These complexes were obtained in high yields and characterized by elemental analysis, 1H NMR, 13 C{1H} NMR and IR spectroscopy, respectively. The molecular structure of 2b has been determined by X‐ray single‐crystal analysis in which the silver atom is in a distorted tetrahedral geometry. An interstitial methanol solvent molecule is hydrogen bonded to the oxygen atom of N‐hydroxysuccinimide molecule. Complex 2f was used to deposit silver films by metal‐organic chemical vapor deposition (MOCVD) for the first time. The silver film obtained at 480 °C is dense and homogeneous, which is composed of many well‐isolated, granular particulates spreading all over the substrate surface. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
90.
Zn-doped AlInAs growth at high temperature, mainly at 750°C, by metalorganic chemical vapor deposition is investigated. When introducing DEZn during AlInAs growth, it is necessary to increase the TMAl flow rate in order to make the layer lattice-matched to InP. This is due to the enhanced In incorporation rather than the large covalent radius of Zn. To clarify the electrical characteristics, the dependence of the DEZn flow rate, the V/III ratio, and the growth temperature are investigated using the van der Pauw Hall method. In our growth system, a GaInAs intermediate layer is effective in preventing n-type inversion in Zn-doped AlInAs, which occurs when it is grown directly on an InP buffer layer. In addition, a large DEZn flow rate is effective for reducing carrier compensation in Zn-doped AlInAs layers grown at 750°C. Si impurities are apparently the cause of the type-inversion and compensation in Zn-doped AlInAs. 相似文献