共查询到19条相似文献,搜索用时 203 毫秒
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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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采用电化学腐蚀法,通过改变腐蚀电流密度制备出不同孔径的多孔硅衬底。通过荧光分光光度计对多孔硅进行光致发光性能测试,测试结果发现腐蚀电流密度会对其光致发光性能产生影响,当腐蚀电流密度为30 mA/cm^2时,制备出的多孔硅光致发光性能较好。通过湿法转移法将化学气相沉积(CVD)法制备出的石墨烯转移到多孔硅表面,利用喇曼光谱对石墨烯进行质量及层数检测。通过荧光分光光度计及傅里叶变换红外光谱仪(FTIR)对复合材料进行表征。结果表明石墨烯可以改变多孔硅表面态,使多孔硅的光致发光性能得到极大的提高。研究成果为多孔硅应用到光学传感器中提供了新的研究方向。 相似文献
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氧与激光辐照对多孔硅光致发光光谱的影响 总被引:1,自引:1,他引:0
毛晋昌 《红外与毫米波学报》1992,11(5):401-405
将化学腐蚀后的多孔硅样品分别置于大气和氧气中,用激光连续辐照其表面.观察到多孔硅的光致发光光谱峰位随辐照时间增加发生蓝移,最后达到稳定,在真空中作同样处理的多孔硅光致发光峰位却没有移动.X射线光电子谱测量结果表明,在大气及氧气中激光辐照的多孔硅层内并未探测到二氧化硅,结合红外吸收光谱实验,认为蓝移的原因可能是氧置换了多孔硅内表面的硅,出现Si-O-Si结构的结果. 相似文献
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通过射频溅射的方法在单晶硅衬底上沉积了β-SiC薄膜,用HF酸(40%)和C2H5OH(99%)的混合溶液对β-SiC薄膜进行了电化学腐蚀处理,形成了多孔β-SiC(PSC)薄膜.利用荧光分光光度计研究了样品的光致发光(PL)特性,用原子力显微镜(AFM)和扫描电子显微镜(SEM)观察了样品腐蚀前后的表面形貌.结果表明:多孔β-SiC薄膜具有较强的蓝光发射特性;通过改变腐蚀时间,可以改变蓝光发射的强度,也可以观察到蓝光-红光同时发射的现象;降低HF酸的浓度,蓝光发射峰明显变弱,并对多孔β-SiC薄膜的发光机理及其微观结构进行了讨论. 相似文献
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多孔β-SiC薄膜的蓝光发射 总被引:4,自引:0,他引:4
通过射频溅射的方法在单晶硅衬底上沉积了βSiC薄膜,用HF酸(40 % )和C2 H5OH(99% )的混合溶液对βSiC薄膜进行了电化学腐蚀处理,形成了多孔βSiC(PSC)薄膜.利用荧光分光光度计研究了样品的光致发光(PL)特性,用原子力显微镜(AFM)和扫描电子显微镜(SEM )观察了样品腐蚀前后的表面形貌.结果表明:多孔βSiC薄膜具有较强的蓝光发射特性;通过改变腐蚀时间,可以改变蓝光发射的强度,也可以观察到蓝光红光同时发射的现象;降低HF酸的浓度,蓝光发射峰明显变弱,并对多孔βSiC薄膜的发光机理及其微观结构进行了讨论. 相似文献
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用于制备SOI材料的基于硅片键合和双层多孔硅剥离的薄外延硅膜转移技术 总被引:2,自引:2,他引:0
采用在阳极化反应时改变电流强度的办法 ,在高掺杂的 P型硅 (111)衬底上制备了具有不同多孔度的双层结构多孔硅层 .用超高真空电子束蒸发技术在多孔硅表面外延生长了一层高质量的单晶硅膜 .在室温下 ,该外延硅片同另一生长有热二氧化硅的硅片键合在一起 ,在随后的热处理过程中 ,键合对可在多孔硅处裂开 ,从而使外延的单晶硅膜转移到具有二氧化硅的衬底上以形成 SOI结构 .扫描电镜、剖面投射电镜、扩展电阻和霍尔测试表明 SOI样品具有较好的结构和电学性能 相似文献
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A. N. Yablonskiy B. A. Andreev D. I. Kryzhkov V. P. Kuznetsov D. V. Shengurov Z. F. Krasilnik 《Semiconductors》2012,46(11):1407-1410
The photoluminescence (PL) excitation spectra of erbium and band-to-band silicon in Si:Er/Si epitaxial structures under high-intensity pulsed optical excitation are studied. It is shown that the nonmonotonic dependence of the PL intensity on the excitation wavelength ??ex near the absorption edge of silicon is due to inhomogeneity in the optical excitation of the Si:Er active layer. The sharp rise in the erbium PL intensity in the spectral range ??ex = 980?1030 nm is due to an increase in the excited part of the Si:Er emitting layer on passing to subband light pumping (??ex > 980 nm) with a low absorption coefficient in silicon because of the effective propagation of the excitation light in the bulk of the structures under study. It is shown that, under the subband optical pumping of Si:Er/Si structures, as also in the case of interband pumping, the exciton mechanism of erbium ion excitation is operative. Excitons are generated under the specified conditions as a result of a two-stage absorption process involving impurity states in the band gap of silicon. 相似文献
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多孔硅(PorousSilicon)是晶体硅于氢氟酸溶液中在硅衬底上形成的多孔态的硅材料。PS可见光区的强烈光辐射使其成为世界范围的研究焦点。本文用电化学方法制得了PS结构,扫描电子显微镜(SEM)的结果表明PS是一个硅的毫微结构量子线的网络,光致发光(PL)谱表明PS发可见红光,而喇曼光谱显示一个在516cm(-1)附近的非对称峰,说明PS是一种新型的硅材料。 相似文献
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Marouan Khalifa Malek Atyaoui Messaoud Hajji Rachid Ouertani Hatem Ezzaouia 《Materials Science in Semiconductor Processing》2013,16(6):1742-1746
We investigated a novel process for purifying metallurgical-grade silicon (MG-Si). MG-Si powder was first treated to form a thin porous silicon layer. This was heated at 900 °C under oxygen to weaken impurity–Si bonds. Samples were then chemically etched with dilute aqueous hydrofluoric acid. To understand the mechanisms in this purification process, structural, chemical composition and optical properties of MG-Si powder before and after treatment were characterized using Fourier-transform infrared (FTIR), inductively coupled plasma-atomic emission (ICP-AES), and photoluminescence (PL) spectroscopy techniques. FTIR studies of treated MG-Si powder revealed the formation of a thin porous silicon layer on the top surface, as evidenced by SiHx vibration peaks. PL spectra show that 30-min HF etching of MG-Si led to an increase in red emission, indicating the formation of porous silicon and suggesting a decrease in impurities. ICP-AES revealed that the process led to significant decreases in the concentrations of 15 different elemental impurities. 相似文献
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Aiming for a more practical route to highly stable visible photoluminescence (PL) from silicon, a novel approach to produce luminescent silicon nanoparticles (Si‐NPs) is developed. Single crystalline Si‐NPs are synthesized by pyrolysis of silane (SiH4) in a microwave plasma reactor at very high production rates (0.1–10 g h?1). The emission wavelength of the Si‐NPs is controlled by etching them in a mixture of hydrofluoric acid and nitric acid. Emission across the entire visible spectrum is obtained by varying the etching time. It is observed that the air oxidation of the etched Si‐NPs profoundly affects their optical properties, and causes their emission to blue‐shift and diminish in intensity with time. Modification of the silicon surface by UV‐induced hydrosilylation also causes a shift in the spectrum. The nature of the shift (red/blue) is dependent on the emission wavelength of the etched Si‐NPs. In addition, the amount of shift depends on the type of organic ligand on the silicon surface and the UV exposure time. The surface modification of Si‐NPs with different alkenes results in highly stable PL and allows their dispersion in a variety of organic solvents. This method of producing macroscopic quantities of Si‐NPs with very high PL stability opens new avenues to applications of silicon quantum dots in optoelectronic and biological fields, and paves the way towards their commercialization. 相似文献
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制备及钝化条件对多孔硅发光性能的影响 总被引:1,自引:1,他引:0
研究了氧化电流密度对多孔硅(PS)PL谱的影响。结果表明,随着氧化电流密度增大,PS的微晶Si平均尺寸减小,且尺寸的微晶Si数量也减少,说明制备条件对钝化PS的发光有影响;PS经适当的高温氧化处理后,其PL谱会发生明显变化;选用含有胺基的正丁胺,采用射频辉光放电法对PS进行钝化处理,在一定程度上提高了PS的发射强度伴随发光峰值的较大蓝移;其钝化PS的荧光谱随钝化温度和钝化时间变化,说明钝化条件对钝化PS的发光有直接影响。由此,可以通过调节制备和钝化条件来获得最大的发光效率和所需要的发光颜色。 相似文献