共查询到20条相似文献,搜索用时 62 毫秒
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用常规电化学方法制备了发射高效可见光的多孔硅样品。对样品进行了光谱研究。用非化学方法从样品表面得到了粉末状荧光物质(非多孔硅膜研磨产物),光谱测定证实它的光致发光光谱与原多孔硅样品光致发光光谱相同,粉末进一步研磨后仍能发出同样的可见光。多孔硅样品还可以实现阴极射线激发发出同样的高效可见光,但易因电子束的轰击而发光强度较快减弱。用扫描电镜(SEM)对多孔硅样品的形貌、结构、荧光粉末的形状、尺寸、多孔硅样品阴极荧光发射区域进行了系统的研究。实验结果表明多孔硅样品一般可分为三层结构:表面层、多孔层和单晶硅衬底,样品荧光是来源于其表面层的。对样品表层组分的x射线光电子谱(XPS)分析表明,此时的多孔硅表层有大量非硅元素存在,如:C、O、F(没考虑H),硅元素的原子个数比只占30%~50%。用同样的电化学方法在单晶硅未抛光面上和多晶硅未抛光面上制得了均匀发射可见光样品。上述实验结果说明,多孔硅的高效可见光发射是来源于样品制备过程中在其表面层中形成的粉末状荧光物质。 相似文献
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《微纳电子技术》2019,(3):187-194
反射率对太阳电池的性能至关重要。采用电化学法在单晶硅衬底上制备多孔硅来降低器件的反射率,并采用快速热退火法对多孔硅层进行磷扩散处理,进而制备了单晶硅太阳电池。扫描电子显微镜(SEM)显示出单晶硅表面形成了孔径均匀的多孔硅层,且孔径随着刻蚀时间的增加而增大;紫外-可见光分光光度计表明,该多孔硅层的反射率在400~1 100 nm的光谱范围达到12%;磷扩散后薄层方块电阻达到42Ω/□,证明多孔硅层促进了磷扩散。最终在850℃、40 s快速热退火扩散条件下,成功制备出了效率为12.32%、短路电流密度为27.99 mA/cm~2、开路电压为0.49 V以及填充因子达到71%的太阳电池。 相似文献
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研究了多孔硅膜的制备、性质和应用。在低于临界电流密度的电流下,在浓氢氟酸中进行阳极处理使硅单晶转变成多孔硅膜。当 N 型硅作阳极处理时,用光照射硅表面以产生阳极反应所必需的空穴。在本实验条件下,从 N 型硅上生成薄膜的速率要比从 P 型硅上生成的快些。其晶体结构与硅单晶相同。利用多孔硅能作成几个微米厚。并且容易氧化形成绝缘体这一特性,对于双极型集成电路提出了一个新的隔离技术。该技术的主要特点是提供了一个形成嵌入穿透 N 型外延层的厚绝缘膜的方法,并且不需要过长的热处理.为试验这一技术的实际应用,已进行了初步的实验。 相似文献
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利用电化学方法在p型重掺杂单晶硅(100)基体上制备了多孔硅薄膜,通过质量计算法得到多孔硅的孔隙率,并研究了多孔硅孔隙率随腐蚀深度变化的规律。利用显微拉曼光谱技术对多孔硅纵切面上的残余应力进行了测量,结果表明,多孔硅的孔隙率随腐蚀时间/深度的增加有先增加后减少的趋势;多孔硅纵向上存在拉伸残余应力,拉伸应力的分布与纵切面上孔隙率的分布成正比,先增大,再减小;到达多孔硅与基体硅的界面处时,拉伸应力减小为零,靠近硅一侧,转变为压应力;残余应力的最大值出现在临近多孔硅表面以下的区域。这主要与多孔硅制备过程中孔内HF酸浓度的降低和硅/电解液表面的电偶层有关。 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
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The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
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The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
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Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
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Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
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A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
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《中国通信》2014,(7)
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks 相似文献
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《中国通信》2014,(8)
正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first 相似文献
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LI Shaoqian 《中国通信》2014,(6):I0001-I0002
The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave (ram-wave) frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications. 相似文献