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阳极氧化条件对多孔硅冷阴极场发射特性的影响 总被引:1,自引:1,他引:0
研究了多孔硅的制备条件对多孔硅冷阴极场发射特性的影响,实验表明多孔硅的制备条件如电解电流密度、电解时间等多孔硅冷阴极的场发射特性有较大的影响。 相似文献
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发光多孔硅微结构及其发光起源探讨 总被引:1,自引:0,他引:1
用制备发光多孔硅样品的常规电化学方法,在未抛光多晶硅表面,成功地制备出了均匀地发射肉眼可分辨的可见光样品。样品的先致发光光谱得到了测定,证明是一种典型的多孔硅光致发光光谱。用扫描电镜对样品的表面形貌、截面结构进行了详细的分析,摄制出了发光多孔硅样品的完整多孔状微结构清晰照片。实验结果认为多孔硅样品可分成三层:表面层、多孔层、单晶硅衬底;而多晶硅表面上制备的发光样品只有两层结构:表面层、多晶硅衬底。文中认为多孔硅可见光发射应来自其表面层,而与层下的多孔层微结构无关。 相似文献
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多孔硅制备工艺的研究 总被引:1,自引:0,他引:1
多孔硅的发光性能与其制备工艺密切相关,本文着重讨论了阳极氧化技术、表面再处理、硅衬底的电学性质等因素对多孔硅质量的影响,给出了合适的工艺条件。 相似文献
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Labview软件控制腐蚀条件,用脉冲电化学腐蚀法制备多孔硅薄膜,其表面形貌用原子力显微镜观察并分析。用可见-紫外分光光度仪测量其反射谱,通过计算得出各种制备条件下,多孔硅薄膜的其它光学参数,即有效折射率neff,吸收系数α,有效介电常数的实部εer,和虚部εei,消光系数K,研究了入射光波长和孔隙率对这些光学常数的影响。 相似文献
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纳米ZnO光学性质研究进展 总被引:4,自引:0,他引:4
介绍了纳米ZnO常见发光谱的发光机制。在室温光致发光谱(PL)中,一般在380 nm处出现紫外发光,也有报道在357和377 nm处的紫外发光,列举了几种不同的发光解释。对于深能级发光,一般在400~550 nm出现连续的发光带,也有观察到深能级的声子伴线和声子复制现象。在低温光致发光谱的紫外发射中,一般观察到由自由激子发射(FX)、中性施主束缚激子发射(D0X)、施主-受主对跃迁峰(DAP)、中性施主束缚激子对应的双电子卫星峰(TES)以及声子伴线。综述了纳米ZnO的喇曼光谱、透射光谱、电致发光谱(EL)的特征,最后展望了纳米ZnO的光学性能研究前景。 相似文献
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Semiconductors - The low-temperature (T = 2 K) optical spectra (transmission, reflection and luminescence) of a compositionally graded CdS1 – xSex/CdS heterostructure with a... 相似文献
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采用水溶性前驱物在乙醇介质中制备了不同[S2-]/[Pb2+]摩尔比例的PbS纳米晶,利用X射线衍射(XRD)、透射电子显微镜(TEM)、紫外-可见吸收光谱(Abs)、光致发光谱(PL)对所制备PbS纳米晶的晶体结构、纳米晶粒径、形貌以及能带结构和发光特性进行了表征,结果表明:随着前驱物[S2-]/[Pb2+]摩尔比例的提高,PbS纳米晶颗粒尺寸从3.9 nm增大到5.9 nm,发光峰值位置从1 009 nm移动到1 486 nm。通过拟合[S2-]/[Pb2+]=0.5条件下PbS纳米晶平均粒径对时间变化曲线,发现该方法下PbS纳米晶所经历的生长机制为Ostwald成熟化。运用经典纳米晶扩散控制生长模型,解释了实验中随着[S2-]/[Pb2+]的提高对溶液中纳米晶生长速率的影响。 相似文献
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Roushdey Salh L. Fitting E. V. Kolesnikova A. A. Sitnikova M. V. Zamoryanskaya B. Schmidt H. -J. Fitting 《Semiconductors》2007,41(4):381-386
High resolution transmission electron microscopy, scanning transmission electron microscopy, and cathodoluminescence have
been used to investigate Si and Ge cluster formation in amorphous silicon-dioxide layers. Commonly, cathodoluminescence emission
spectra of pure SiO2 are identified with particular defect centers within the atomic network of silica including the nonbridging oxygen hole center
associated with the red luminescence at 650 nm (1.9 eV) and the oxygen deficient centers with the blue (460 nm; 2.7 eV) and
ultraviolet band (295 nm; 4.2 eV). In Ge+ ion-implanted SiO2, an additional violet emission band appears at 410 nm (3.1 eV). The strong increase of this violet luminescence after thermal
annealing is associated with formation of low-dimension Ge aggregates such as dimers, trimers, and higher formations, further
growing to Ge nanoclusters. On the other hand, pure silica layers were modified by heavy electron beam irradiation (5 keV;
2.7 A/cm2), leading to electronic as well as thermal dissociation of oxygen and the appearance of under-stoichiometric SiOx. This SiOx will undergo a phase separation and we observe Si cluster formation with a most probable cluster diameter of 4 nm. Such largely
extended Si clusters will diminish the SiO2-related luminescence and Si-crystal-related luminescence in the near IR.
The text was submitted by the authors in English. 相似文献
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研究了碲酸盐玻璃的拉曼光谱和红外光谱,分析了OH-对掺Er3 碲酸盐玻璃上转换发光的影响机制。实验结果表明,氧氟碲酸盐玻璃(TPF)的声子能量高于氧氯碲酸盐玻璃(TPC)的声子能量,但是Er3 掺杂TPF玻璃上转换发光强度也高于Er3 掺杂TPC玻璃。除水实验发现这种现象可归因于OH-的影响。随OH-浓度降低,Er3 的荧光寿命和上转换荧光都增加。在实验中,OH-对Er3 上转换发光的影响大于声子能量对Er3 上转换发光的影响,导致Er3 掺杂TPF玻璃上转换发光强度高于Er3 掺杂TPC玻璃的上转换发光。研究结果有助于进一步提高Er3 的发光效率。 相似文献
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A. T. Hunter H. Kimura H. M. Olsen H. V. Winston 《Journal of Electronic Materials》1986,15(4):215-219
Czochralski GaAs grown with In incorporated into the melt has large regions with fewer than 100 cm-2 dislocations. We have examined the effect of these dislocations on substrate and device properties. Infrared transmission
images reveal dark filaments of high EL2 concentration a few tens of microns in diameter surrounding dislocations, Cathodo
and photoluminescence images show orders of magnitude contrast in band-edge luminescence intensity near dislocations. Single
dislocations appear to be surrounded by bright rings ˜200 μm in diameter in luminescence images, with dark spots 50 to 75
μm across centered on the dislocation. More complex luminescence structures with larger dark regions (˜150 μ across) and central
bright spots are centered on small dislocation clusters. Differences in lifetime of photogenerated electrons or holes are
the most likely cause of the luminescence contrast. Anneals typical of our post-implant processing substantially lower the
luminescence contrast, suggesting the defect lowering the lifetime is removed by annealing. This may partially explain why
we do not observe any effect of dislocation proximity on the properties of devices made in the material, in spite of the enormous
luminescence contrast observed near dislocations. 相似文献