排序方式: 共有65条查询结果,搜索用时 15 毫秒
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采用射频磁控反应溅射技术制备不同Si层厚度的a-Si/a-SiNx超晶格材料.利用红外光谱(IR)、能谱(EDS)、X射线衍射谱(XRD)、吸收谱和光致发光(PL)谱对超晶格材料的成分、结构和发光特性进行研究.结果表明,样品的光学吸收边和PL峰随着Si层的厚度的变化而发生明显偏移,观察到了明显的量子限制效应.在氮气保护下以1000℃对样品进行热退火处理,发现Si层厚的样品退火后发光峰相对于退火前发生了蓝移,这归因于样品中nc-Si颗粒的形成. 相似文献
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采用等离子体化学气相沉积技术制备了两种不同非晶硅层厚度的氮化硅/氢化非晶硅/氮化硅三明治结构,研究了不同能量激光退火对薄膜晶化的影响。通过拉曼分析,发现在激光能量为320mJ时,样品开始晶化,随着能量的提高晶化程度增加,在340mJ时达到最大。根据拉曼晶化峰的偏移,计算得出硅量子点尺寸为2.8nm和4.7nm,表明三明治结构对形成的硅量子点的尺寸具有限制作用。设计并制备了基于该结构的电致发光器件,在偏压大于10V时,在室温下可观测到电致发光。发现不同激光能量下晶化后的样品的电致发光强度不同,发光峰位在680nm和720nm附近。分析表明电致发光来源可以归结为电子空穴对在硅量子点中的辐射复合发光。 相似文献
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We are the first to report the realization of quasiperiodic amorphous semiconductor superlattices composed of alternating layers of a-Si:H and a-SiNx:H to form a Fibonacci sequence in which the ratio of incommensurate periods is equal to the golden mean T=(1+5~(1/2))/2. In the present work new results of low-angle X-ray diffraction pattern with Lf = τLa + Lb= 148A are well consistent with a numerical calculation using formula Km,n = 2τLf-1 (mτ +n), which further demonstrate the peculiarities of quasiperiodicity. From electrical measurements done along the film plane, the feature of temperature dependence of σd suggests that there are two transport pathes at different temperature region. We tentatively explain this phenomenon in terms of the different space charge density and mobility edge in two distinct building blocks A and B of quasiperiodic a-Si:H/a-SiNx:H super-lattices. 相似文献
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激光干涉结晶法制备三维有序分布的nc-Si阵列 总被引:1,自引:0,他引:1
利用准分子激光干涉结晶法使a Si∶H/a SiNx∶H多层膜中的超薄a Si∶H层定域晶化 ,成功地制备出三维有序分布的nc Si阵列。原子力显微镜 (AFM )、微区拉曼 (micro Raman)光谱及剖面透射电子显微镜 (X TEM)的分析结果揭示在晶化薄膜中已形成平均尺寸约为 3 6nm ,横向周期 2 μm ,纵向周期与a Si∶H/a SiNx∶H多层膜周期 (14nm)相等的nc Si阵列。 相似文献
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采用射频磁控反应溅射技术与热退火处理制备了nc-Si/SiN_x多量子阱材料.对样品进行了小角度XRD、Raman光谱、吸收光谱测试,研究了其结构和光学性质.采用皮秒脉冲激光单光束Z-扫描技术研究了样品在非共振吸收区的三阶非线性光学特性.实验结果表明,其非线性折射率为负值,非线性吸收属于双光子吸收.由实验数据计算得材料三阶非线性极化率为7.50×10~(-8)esu,该值比体硅材料的三阶非线性极化率大4个数量级.对材料光学非线性产生的机理进行了探讨,认为材料的非线性极化率的增加来源于材料量子限制效应增强.Abstract: The nc-Si/SiN_x multi-quantum well (MQW)was prepared by RF magnetron sputtering technique and thermal annealing. The sample was tested by low-angle XRD, Raman spectrometry and absorption spectrometry, and its structure and optical properties were studyed. Nonlinear optical properties of nc-Si/SiN_x MQW were probed by a Z-Scan Technique. The experimental results show that the nonlinear refractive index of the sample is a negative value and the nonlinear absorption is two-photon absorption. After calculating, it is obtained that X~((3)) of the sample is 7.50 10~(-8)esu, the value of nc-Si/SiN_x MQW is 4 orders of magnitude higher than that of bulk Silicon. The nonlinear mechanism of the material was discussed. The enhancement of nonlinear refractive index is mainly attributed to the enhancement of quantum confinement. 相似文献
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用溶胶-凝胶法制得了In2O3纳米颗粒与Eu3 共掺的SiO2薄膜.使用X-射线衍射证实体系中形成了In2O3纳米颗粒,其数密度可以通过改变铟的掺杂浓度来进行良好的控制.在薄膜的光致发光光谱中观察到Eu3 离子的5Do-7FJ(J:O-4)特征发射峰,In2O3纳米颗粒的掺入使Eu3 的光致发光得到显著增强.通过光致发光激发光谱的测量进一步研究了In2O3纳米颗粒对Eu3 的光致发光增强的机制. 相似文献
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