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61.
Er3+ ions embedded in silica thin films co-doped by SnO2 nanocrystals are fabricated by sol-gel and spin coating methods. Uniformly distributed 4-nm SnO2 nanocrystals are fabricated, and the nanocrystals showed tetragonal rutile crystalline structures confirmed by transmission electron microscope and X-ray diffraction measurements. A strong characteristic emission located at 1.54 μm from the Er3+ ions is identified, and the influences of Sn doping concentrations on photoluminescence properties are systematically evaluated. The emission at 1.54 μm from Er3+ ions is enhanced by more than three orders of magnitude, which can be attributed to the effective energy transfer from the defect states of SnO 2 nanocrystals to nearby Er3+ ions, as revealed by the selective excitation experiments. 相似文献
62.
本文介绍二种新型液体密度的传感器原理、测量方法、实验结果以及它们在化学实验、化工与医药工业中自动化检测密度方面的应用。 相似文献
63.
Preparation of a Single Layer of Luminescent Nanocrystalline Si Structures by Laser Irradiation Method 下载免费PDF全文
KrF excimer laser annealing on ultrathin hydrogenated amorphous Si films with various initial Si thicknesses is carried out to obtain a single layer of nanocrystalline Si structures. It is found that Si nanograins can be obtained with the area density as high as 10^11 cm^-2 under the irradiation with suitable laser fluence. Raman and planar transmission electron microscopy are used to characterize the formation process of Si nanocrystals from amorphous phase. Moreover, a strong photoluminescence is observed at room temperature from well-relaxed nanocrystalline Si structures. 相似文献
64.
A new method of phase-modulated excimer laser crystallization is adopted to fabricate the patterned nanometer-sized crystalline silicon (nc-Si) dots within the sandwiched structure (a-SiNx:H/a-Si:H/a-SiNx:H) films. The results of transmission electron microscopy, electron diffraction and Raman scattering show the ultra-thin and single-layer nc-Si films were patterned in the lateral direction and the size of crystallites is controlled by the thickness of as-deposited a-Si film in the longitudinal direction. The effects of the laser energy density on the structures of the samples and the crystallization mechanism are discussed. 相似文献
65.
采用射频磁控溅射方法制备了两种用于相变存储器的Ge1Sb2Te4和Ge2Sb2Te5相变薄膜材料,对其结构、电学输运性质和恒温下电阻随时间的变化关系进行了比较和分析.X射线衍射(XRD)和原子力显微镜(AFM)的结果表明:随着退火温度的升高,Ge1Sb2Te4薄膜逐步晶化,由非晶态转变为多晶态,表面出现均匀的、
关键词:
硫系相变材料
1Sb2Te4')" href="#">Ge1Sb2Te4
2Sb2Te5')" href="#">Ge2Sb2Te5 相似文献
66.
Enhanced photoluminescence (PL) at room temperature from thermally annealed a-Si:H/SiO2 multilayers is observed through the step-by-step thermal post-treatment. The correlation between the PL and the crystallization process is studied using temperature-dependent PL, Raman, cross section high-resolution transmission electron microscopy (XHRTEM) and x-ray diffraction (XRD) techniques. An intensified PL band around 820 nm is discovered from the sample annealed near the crystallization onset temperature, which is composed of two peaks centred at 773 nm and 863 nm, respectively. It is found that the PL band centred at 863 nm is related to the pseudo nanocrystal (p-nc-Si) silicon, and the PL band centred at 773 nm is attributed to Si = O bonds stabilized in the p-nc-Si surface. 相似文献
67.
在等离子体增强化学气相淀积(PECVD)系统中,采用a-Si∶H层淀积与原位等离子体氧化相结合的逐层生长的方法成功制备出a-Si∶H/SiO2多层膜 (ML);利用限制性结晶原理通过两步退火处理使a-Si∶H层晶化获得尺寸可控的nc-Si/SiO2 ML,并观察到室温下的蓝光发射;结合Raman散射和剖面透射电子显微镜技术分析了nc-Si/SiO2 ML的结构特性;通过对晶化样品光致发光谱和紫外-可见光吸收谱的研究,探讨了蓝光发射的起源.
关键词:
纳米硅多层膜
等离子体氧化
蓝光发射
热退火 相似文献
68.
69.
Intensive blue photoluminescence (PL) was observed at room temperature from the nanocrystalline-Si/SiO2 (nc-Si/SiO2) multilayers (MLs) obtained by thermal annealing of SiO/SiO2 MLs for the first time. By controlling the size of nc-Si formed in SiO sublayer from 3.5 to 1.5 nm, the PL peak blueshifts from 457 to 411 nm. Combining the analysis of TEM, Raman and absorption measurement, this paper attributes the blue PL to multiple luminescent centres at the interface of nc-Si and SiO2. 相似文献
70.
利用胶体小球掩蔽刻蚀技术,制备了单晶硅纳米阵列,利用原子力显微镜观察了硅阵列的表面形貌,实验结果表明,硅柱阵列具有高密度和较好的均匀性。同时研究了单晶硅纳米阵列的场电子发射特性。为了提高样品的场发射性能,在所制备的单晶硅有序纳米阵列上生长了一层非晶碳薄膜。与单晶纳米硅柱阵列相比,覆盖有非晶碳膜的样品的场电子发射特性有了明显的改善,表现在场发射的开启电场下降,同时场发射增强因子得到增加。结果表明非晶碳膜确实能够降低电子发射的表面有效势垒,从而增强了场电子发射特性。 相似文献