氨化Ga2O3/Nb薄膜制备GaN纳米线

采用射频磁控溅射技术先在硅衬底上制备Ga2O3/ Nb薄膜,然后在900℃时于流动的氨气中进行氨化制备GaN纳米线.用X射线衍射(XRD)、傅立叶红外吸收光谱(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)详细分析了GaN纳米线的结构和形貌.结果表明:采用此方法得到的GaN纳米线为六方纤锌矿结构,其纳米线的直径大约在50～100nm之间,纳米线的长约几个微米.室温下以325nm波长的光激发样品表面,只显示出一个位于364.4nm的很强的紫外发光峰.最后,简单讨论了GaN纳米线的生长机制.     

氨化Si基Ga2O3/Co薄膜制备GaN纳米线

采用磁控溅射技术先在硅衬底上制备Ga2O3/Co薄膜,然后在900℃时于流动的氨气中进行氨化反应制备GaN薄膜.X射线衍射(XRD)、傅立叶红外吸收光谱(FTIR)、选区电子衍射(SAED)和高分辨透射电子显微镜(HRTEM)的分析结果表明,采用此方法得到了六方纤锌矿结构的GaN单晶纳米线.通过扫描电镜(SEM)观察发现纳米线的形貌,纳米线的尺寸在 50～200nm之间.     

氨化Si基Ga2O3/Ti制备GaN纳米线

采用磁控溅射技术先在硅衬底上制备Ga2O3/Ti薄膜,然后在950℃时于流动的氨气中进行氨化反应制备GaN薄膜.X射线衍射(XRD)、傅立叶红外吸收光谱(FTIR)、选区电子衍射(SAED)和高分辨透射电子显微镜(HRTEM)的结果表明采用此方法得到了六方纤锌矿结构的GaN单晶纳米线.通过扫描电镜(SEM)观察发现纳米线的形貌,纳米棒的尺寸在50～150nm之间.     

氨化Si基Ga2O3/V薄膜制备GaN纳米线

为了制备高质量的GaN纳米结构,采用磁控溅射技术先在硅衬底上制备Ga2O3/V薄膜,然后在流动的氨气中进行氨化反应,成功制备出GaN纳米线.采用X射线衍射(XRD)、傅里叶红外吸收光谱(FTIR)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对样品进行分析.研究结果表明,采用此方法得到了六方纤锌矿结构的GaN纳米线,且900℃时制备的纳米线质量最好,直径在60nm左右,长度达到十几微米.     

氨化Ga2O3/TiO2/Si薄膜制备GaN纳米线

为了制备高质量的GaN纳米结构,采用磁控溅射技术先在硅衬底上制备Ga2O3／TiO2薄膜,然后在950℃时于流动的氨气中进行氨化反应,成功制备出GaN纳米线．采用X射线衍射（XRD）、傅里叶红外吸收光谱（FTIR）、扫描电子显微镜（SEM）和高分辨透射电子显微镜（HRTEM）对样品进行分析．研究结果表明,采用此方法得到了六方纤锌矿结构的GaN单晶纳米线,纳米线的直径在100～400nm,纳米线的长度在3～10μm．     

氨化温度对氨化Si基Ga2O3/Cr膜制备GaN纳米结构的影响

采用磁控溅射的方法在Si(111)衬底上溅射沉积Ga2O3/Cr膜,并通过氨化的方法在Si(111)衬底上成功合成了六方纤锌矿GaN纳米结构材料,研究了不同的氨化温度对合成GaN纳米材料的影响.采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、透射电子显微镜(TEM)、高分辨透射电子显微镜(HR-TEM)、傅里叶红外吸收(FTIR)光谱来检测样品的形态,结构和成分,并且讨论了GaN纳米结构的生长机理.研究结果表明,在Cr催化合成GaN纳米结构的过程中,氨化温度对其有重要影响,最佳温度是950℃.     

氨化Si基Ga2O3/In制备GaN薄膜

研究了Ga2O3/In 膜反应自组装制备GaN薄膜,再将Ga2O3/In膜在高纯氨气气氛中氨化反应得到GaN薄膜,用X射线衍射(XRD),傅里叶红外吸收(FTIR),扫描电镜(SEM),原子力显微镜(AFM),透射电镜(TEM)对样品进行结构,形貌的分析.测试结果表明:用此方法得到了六方纤锌矿结构的GaN多晶膜,且900℃时成膜的质量最好.     

氨化Ga2O3/Pd/Sapphire薄膜制备GaN纳米线

利用金属元素钯作催化剂,采用磁控溅射后氨化法,成功的在Sapphire衬底上制备出GaN纳米线。X射线衍射和X射线光电子能谱研究显示合成的纳米线具有六方纤锌矿GaN结构。通过扫描电子显微镜,透射电子显微镜和高分辨透射电子显微镜观察分析得出GaN纳米线为单晶结构,其纳米线的直径约为10～60nm,长度达几十个微米。室温下以325nm波长的光激发样品表面,发现GaN带边发光峰有较弱的蓝移。最后简单讨论了GaN纳米线的生长机制。     

氨化Si基Ga2O3/In2O3制备GaN薄膜

研究了Ga2O3/In2O3 膜反应自组装制备GaN薄膜,再将Ga2O3/In2O3膜在高纯氨气气氛中氨化反应得到GaN薄膜,用X射线衍射 (XRD),傅里叶红外吸收(FTIR),扫描电镜(SEM)和透射电镜(TEM)对样品进行结构、形貌的分析.测试结果表明,用此方法得到了六方纤锌矿结构的GaN多晶膜,且900℃时成膜的质量最好.     

化学气相沉积法制备GaN纳米线及其形貌结构和生长机理研究

采用化学气相沉积(CVD)法,分别以Ni、Au为催化剂,氨化金属Ga制备出GaN纳米线。运用SEM,EDX,TEM等表征手段分析了GaN纳米线的形貌与结构。通过改变氨化温度、生长时间、催化剂、衬底以及Ga源和衬底间的距离等生长条件,研究了其对GaN纳米线形貌和结构的影响,通过分析探讨纳米线的生长过程与机制,得到了生长GaN纳米线的最佳工艺。     

Effect of the ammoniating time on microstructure and morphology of one-dimensional Mg-doped GaN nanowires catalysed with Au

Mg-doped GaN nanowires have been successfully synthesised on Si(1?1?1) substrates by magnetron sputtering through ammoniating Ga₂O₃/Au thin films, and the effect of ammoniating time on microstructure and morphology were analysed in detail. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy and photoluminescence spectrum were carried out to characterise the microstructure, morphology and optical properties of the GaN samples. The results demonstrate that the nanowires after ammonification at 900°C for 15?min are single crystal GaN with a hexagonal wurtzite structure and high crystalline quality, having the size of 50–80?nm in diameter, more than 10 microns in length and good emission properties. The growth direction of this nanowire is parallel to [0?0?1] direction of hexagonal unit cell. Ammoniating time has a great impact on the microstructure, morphology and optical properties of the GaN nanowires.     

Synthesis of single-crystal GaN nanowires on Si(111) substrate by ammonification technology

GaN nanowires have been synthesized on Si(111) substrate through ammoniating Ga₂O₃/BN films under flowing ammonia atmosphere at the temperature of 900 °C. The as-synthesized GaN nanowires were characterized by X-ray diffraction (XRD), selected-area electron diffraction (SAED), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results demonstrated that the nanowires are hexagonal wurtzite GaN and possess a smooth surface with diameters ranging from 40 to 100 nm and lengths up to several tens of micrometers. The growth mechanism of crystalline GaN nanowires is discussed briefly.     

Fabrication of GaN nanowires on Pd-coated sapphire substrates by magnetron sputtering technique

Large-scale GaN nanowires were successfully synthesized through ammoniating Ga₂O₃/Pd films sputtered on the sapphire(001) substrates. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, photoluminescence and Raman spectrum were used to characterize the specimens. The results demonstrate that nanowires are single crystal with hexagonal wurtzite structure and have good optical properties. Raman scattering appears broadened and asymmetric compared with those of bulk GaN due to its polycrystalline nature. In addition, the growth mechanism of GaN nanowires is briefly discussed.     

The growth of heavily Mg-doped GaN thin film on Si substrate by molecular beam epitaxy

This paper reports the growth of p-GaN by molecular beam epitaxy. During growth, reflection high electron energy diffraction displayed streaky pattern. Hall Effect measurement indicated a hole concentration of 3.90 × 10²⁰ cm^− 3. Scanning electron microscopy and X-ray diffraction measurements revealed that p-GaN has high structural quality. Photoluminescence spectrum showed that band edge emission was found at 354.1 nm, significantly shifted from usual reported value, i.e. 364 nm. The shift was attributed to Burstein-Moss effect. In addition, a broad emission peak at 387.5 nm was also observed which was due to the transition from conduction band edge to Mg acceptor level. Moreover, the presence of 657 cm^− 1 Raman peak also confirmed the heavy Mg-doped characteristic in p-GaN.     

GaN nanowires grown on silicon substrates engraved using stainless-steel micro-tip

GaN nanostructures have been synthesized on silicon substrates using chemical vapor deposition. Prior to growth silicon substrates were engraved using stainless-steel micro-tips. Straight as well as twisted nanowires were observed along the engraved lines/regions. Straight nanowires were few tens of microns in length and the twisted ones were few microns in length with diameter variation between 30 nm and 100 nm. The electron microscopy analysis indicates that the nanowires were grown parallel to the c-axis and possible growth mechanism is described. Raman scattering indicates good quality of nanowires exhibiting intense E₂(high) mode and A₁(LO) mode and a huge red-shift in the mode position indicates nano-size effects. Such engraved substrates without any explicit catalyst can provide site controlled growth of nanowires and this methodology is extendable for growing nanowires of related materials.     

Fabrication of needle-shaped GaN nanowires by ammoniating Ga2O3 films on MgO layers deposited on Si (111) substrates

Needle-shaped GaN nanowires have been synthesized on Si (111) substrate through ammoniating Ga₂O₃/MgO films under flowing ammonia atmosphere at the temperature of 950 °C. The as-synthesized GaN nanowires were characterized by X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM). The results demonstrate that these nanowires are hexagonal GaN and possess a smooth surface with an average diameter about 200 nm and a length ranging from 5 μm to 15 μm. In addition, the diameters of these nanowires diminish gradually. The growth mechanism of crystalline GaN nanowires is discussed briefly.     

化学气相沉积法制备GaN纳米线和纳米棒

采用浸渍法在未抛光的硅衬底上涂抹一层NiCl2薄膜,通过化学气相沉积法(CVD)制备出高质量的GaN纳米线和纳米棒.X射线衍射(XRD)、傅立叶红外吸收光谱(FTIR)、选区电子衍射(SAED)和高分辨透射电子显微镜(HRTEM)的分析结果表明,采用此方法得到了六方纤锌矿结构的GaN单晶纳米线.通过扫描电镜(SEM)观察发现纳米线的形貌,纳米线的直径在50～200nm之间,纳米棒的直径在200～800nm之间.