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根据非晶态半导体的能带理论,讨论了分层优化薄膜电致发光方案中非晶二氧化硅加速层中的电子在高电场中的输运行为.研究结果表明:在高电场下,由于电场的存在降低了陷阱之间的平均势垒高度.在费密能级附近处的杂质及缺陷定域态和导带尾定域态中,电子的输运主要表现为电场增强的热辅助式跳跃传导;而在导带扩展态中,电子的输运仍像晶态半导体那样表现为共有化运动.此外,以实验数据为基础,计算出了非晶二氧化硅中电子的迁移率、最小金属电导率、导带迁移率边界状态密度及费密能级处的状态密度.
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The synthesis of zinc oxide (ZnO) nanowires is achieved by vapor phase transportation (VPT) method. The designed quartz tube, whose both ends are narrow and the middle is wider, is used to control the growth of ZnO nanowires. Dielectrophoresis (DEP) method is employed to align and manipulate ZnO nanowires which are ultrasonic dispersed and suspended in ethanol solution. Under the dielectrophoretic force, the nanowires are trapped on the pre-patterned electrodes, and further aligned along the electric field and bridge the electrode gap. The dependence of the alignment yield on the applied voltage and frequency is investigated. 相似文献
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介绍了新制备的TFEL发光材料ZnO(S):Ce^3 ,测量了它的PL和EL特性,结果显示:这种材抖的TFEL为Ce^3 的发光,有较好的颜色组成(446nm,493nm),可望用于监色TFEL. 相似文献
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Epitaxial Growth and Characteristics of Nonpolar a-Plane InGaN Films with Blue-Green-Red Emission and Entire In Content Range 下载免费PDF全文
Nonpolar (11■0) plane InxGa1-x N epilayers comprising the entire In content (x) range were successfully grown on nanoscale Ga N islands by metal-organic chemical vapor deposition.The structural and optical properties were studied intensively.It was found that the surface morphology was gradually smoothed when x increased from 0.06 to 0.33,even though the crystalline quality was gradually declined,which was accompanied by the appearance of phase separation in the Inx 相似文献
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A simple method is adopted to grow ZnO nanofibers laterally among the patterned seeds designed in advance on silicon substrate. The preparation of seed lattices is carried out by lithographing the metal zinc film evaporated on the substrate. A layer of aluminum is covered on the zinc layer to prevent the ZnO nanorods vertically growing on the top surface. After oxidation, the patterned ZnO/Al2O3 spots are formed at the sites for the horizontal growth of ZnO nanofibers by the vapor phase transportation (VPT) method using the zinc powders as source material. 相似文献
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Ⅱ-Ⅵ族直接带隙化合物半导体氧化锌(ZnO)的禁带宽度为3.37 eV,室温下激子束缚能高达60 meV,远高于室温热离化能(26 meV),是制造高效率短波长探测、发光和激光器件的理想材料。历经10年的发展,ZnO基半导体的研究在薄膜生长、杂质调控和器件应用等方面的研究获得了巨大的进展。本文主要介绍了以国家"973"项目(2011CB302000)研究团队为主体,在上述方面所取得的研究进展,同时概述国际相关研究,主要包括衬底级ZnO单晶的生长,ZnO薄膜的同质、异质外延,表面/界面工程,异质结电子输运性质、合金能带工程,p型掺杂薄膜的杂质调控,以及基于上述结果的探测、发光和激光器件等的研究进展。迄今为止,该团队已经实现了薄膜同质外延的二维生长、硅衬底上高质量异质外延、基于MgZnO合金薄膜的日盲紫外探测器、可重复的p型掺杂、可连续工作数十小时的同质结紫外发光管以及模式可控的异质结微纳紫外激光器件等重大成果。本文针对这些研究内容中存在的问题和困难加以剖析并探索新的研究途径,期望能对ZnO材料在未来的实际应用起到一定的促进作用。 相似文献
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矿物药是中国传统药学中不可缺少的重要组成部分。禹余粮作为常用矿物药之一,在临床上有着广泛的使用和确切的疗效,长期用于治疗久泻,便血和崩漏带下。由于禹余粮原矿物成因复杂,通常由多种矿物组成,且组成比例不一,导致目前市场矿物药禹余粮品种来源较混乱,质量参差不齐,真假难以分辨。2010版《中国药典》所收载矿物药禹余粮的质量控制标准仅有简单的性状和铁盐的化学鉴别项目,不能很好的控制禹余粮的质量。通过FTIR方法建立矿物药禹余粮FTIR指纹图谱,并对禹余粮炮制前后及伪品FTIR图谱进行了比较分析。对不同产地和批次18份禹余粮样品进行分析,FTIR指纹图谱相似度评价以计算共有峰透光率的夹角余弦值获得。结果显示,禹余粮样品的FTIR指纹图谱相似度、相关系数均大于0.90;禹余粮生品、炮制品、伪品红外图谱存在较大差异。阐述了利用FTIR指纹图谱研究禹余粮的成分特征,能够快速、简便地区分真伪及炮制前后的禹余粮样品。禹余粮FTIR指纹图谱的建立为矿物药禹余粮质量评价提供了新方法,为《中国药典》禹余粮药材质量标准的完善提供了依据。 相似文献
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