M. Mozibur Rahman
材料科学技术（英文）
The nano-structural Al-doped ZnO thin films of different morphologies deposited on glass substrate were successfully fabricated at substrate temperature of 350 °C by an inexpensive spray pyrolysis method. The structural, electrical, optical and photoluminescence properties were investigated. X-ray diffraction study revealed the crystalline wurtzite (hexagonal) structure of the films with nano-grains. Scanning electron microscopy (SEM) micrographs indicated the formation of a large variety of nano-structures during film growth. The spectral absorption of the films occurred at the absorption edge of ˜410 nm. In the present study, the optical band gap energy 3.28 eV of ZnO decreased gradually to 3.05 eV for 4 mol% of Al doping. The deep level activation energy decreased and carrier concentrations increased substantially with increasing doping. Exciting with the energy 3.543 eV (λ=350 nm), a narrow and a broad characteristic photoluminescence peaks that correspond to the near band edge (NBE) and deep level emissions (DLE), respectively emerged.
关键词:
Thin film
C.Arnoult
,
X.Devaux
,
H.Rinnert
,
M.Vergnat
材料科学技术（英文）
Ultrafine powders containing alumina nanowires are synthesized by DC arc plasma from pure aluminium metal. Nanowires grow only when reactive gases are composed of nitrogen and less than ten percent of oxygen. Nanowires have the diameters ranging from 20 to 80 nm and lengths ranging from hundreds nanometers to tens of micrometers. A first assumption of the mechanism process is proposed, in which nanowires grow starting directly from the aluminium. Photoluminescence measurements show that the powders have three emission peaks around 435, 530 and 750 nm resulting from different kinds of defects such as oxygen vacancies, aluminium interstitial ions and surface defects.
关键词:
Nanowires
,
null
,
null
,
null
K.M.K. Srivatsa
材料科学技术（英文）
Hexagonally well-faceted microcrystals of ZnO have been grown by thermal evaporation of Zn powder in oxygen ambient at 700 °C under atmospheric pressure. It has been observed that the properties (size and quality) of ZnO microcrystals have a strong dependence on the reactor temperature at which the oxygen gas is admitted into the growth zone. The microcrystals grown with oxygen admittance at 450 °C have a length of 1 ¹m and a diameter of 0.75 μm while that grown with oxygen admittance at 600 °C have a length of 1.5-2 μm and a diameter of 1 μm. Room temperature photoluminescence spectra show a ultraviolet (UV) emission peak at 385 nm with a green band emission at around 500 nm. The UV-to-green band emission ratio for the microcrystals grown with oxygen admittance at 450 °C is observed to be 1.25 and the ratio decreases to 0.45 for the sample grown with oxygen admittance at 600 °C.
关键词:
ZnO microcrystals
董雷
,
张瑞康
,
江山
,
赵圣之
,
刘水华
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2010.03.009
本文详细研究了采用Cl2/H2刻蚀气体时,ICP刻蚀系统对InP/InGaAsP材料表面损伤的影响.通过设计特殊结构的InP/InGaAsP多量子阱结构,测量刻蚀区域及非刻蚀区域的光荧光强度的变化,并结合高斯深度分布模型对刻蚀损伤进行定量研究.详细研究ICP刻蚀系统中的压强、ICP功率、RF功率以及Cl1/H2刻蚀气体组分对损伤程度的影响.基于这些结果优化得到一组低损伤参数,最终实现刻蚀损伤深度小于16nm.
关键词:
等离子体刻蚀
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干法刻蚀损伤
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感应耦合等离子体
,
光荧光
沈波
,
张荣
,
郑有炓
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2000.04.012
研究了调制掺杂AlxGa1-xN/GaN异质结中与二维电子气 (2DEG) 有关的光致发光,发现温度40 K时Al0.22Ga0.78N/GaN 异质结中2DEG 与光激发空穴复合形成的发光峰位于3.448 eV, 低于GaN 自由激子峰45 meV.由于AlxGa1-xN/GaN 界面极强的压电极化场的影响,光激发空穴很快扩散进GaN 平带区,导致2DEG 与光激发空穴复合几率很低.在GaN 中接近Al0.22Ga0.78N/GaN 界面处插入Al0.12Ga0.88N 限制层用于抑制光激发空穴的扩散,从而大大增强了2DEG发光峰的强度.还研究了2DEG发光峰随温度和光激发强度的变化.
关键词:
GaN
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二维电子气(2DEG)
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异质结
,
光致发光
黄珊
,
王继刚
,
刘松
,
张玥晨
,
钱柳
,
梁杰
新型炭材料
以Si粉、SiO2粉和人造石墨为原料，在1480℃、4 kW、80 min的真空微波辐照条件下快速高效地合成SiC纳米线。利用SEM、TEM、XRD等对所得产物的微观结构解析表明，在未使用催化剂的条件下，基于气固( VS)机制可成功制备出β型SiC。根据坩埚中的部位不同，所得SiC呈现出不同的形貌。坩埚上层的产物呈亮绿色，较为纯净，主要为直径约150 nm的纳米棒，并含有部分微米级SiC晶粒，表面氧化迹象不明显。其余部分产物呈灰绿色，主要是直径为20~50 nm的SiC/SiO2同轴纳米线(表层的SiO2厚度约2 nm)，并夹杂有未反应完全的石墨和SiO2。利用波长为240 nm的激发光分别对SiC纳米棒和同轴纳米线的光致发光特性的测试表明，两者均可观察到峰位在390 nm左右的发射峰，此结果与所报道的β-SiC纳米材料的发光性能相比，蓝移程度更高。
关键词:
微波法
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碳化硅
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纳米线
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结构表征
,
光致发光
陆映东
,
常永勤
,
孔广志
,
王明文
,
郭佳林
,
龙毅
,
张寅虎
,
林杰
功能材料
在常压条件下采用气相沉积方法制备出SnO_2纳米线,X射线衍射和Raman光谱结果均表明制备出来的产物为金红石结构.在样品的光致发光谱中观察到缺陷发光峰.研究还发现蒸发源及其放置时间在SnO_2纳米线的形成过程中起重要的作用.
关键词:
SnO_2纳米线
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常压
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气相沉积
,
光致发光
