共查询到20条相似文献,搜索用时 359 毫秒
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基于pin结构的a-Si∶H太阳能电池中的空间电荷效应,讨论了a-Si/poly-Si叠层太阳能电池的稳定性.结果表明,在光照射下,光生空穴俘获造成了a-Si∶H中正空间电荷密度的增加,从而改变了电池内部的电场分布,提高了a-Si∶H薄膜中的电场强度.空间电荷效应不会给a-Si/poly-Si叠层结构中的a-Si∶H薄膜带来准中性区(低场"死层"),也没有发生a-Si/poly-Si叠层太阳能电池的光诱导性能衰退,因而a-Si/poly-Si叠层结构太阳能电池具有较高的稳定性. 相似文献
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我们利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对a-Si,a-Si∶H,a-Si∶Cl和μc-Si薄膜进行了观测。文中讨论了a-Si(或a-Si∶H,a-Si∶Cl)和μc-Si薄膜的生长机理;提出了可能的结构模型,即a-Si(或a-Si∶H,a-Si∶Cl)薄膜具有卵石状结构或柱状结构,μc-Si薄膜具有锥状结构。 相似文献
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以玻璃为衬底,室温条件下采用直流磁控溅射技术制备了Glass/Al/a-Si样品.在H2,N2和空气3种不同气氛中进行了退火处理.分别采用XRD,Raman光谱和SEM研究了退火气氛对a-Si薄膜销诱导晶化(AIC)过程的影响.XRD实验结果表明:a-Si薄膜在H2气氛中400℃下经过90min的退火处理就能得到结晶较好的poly-si薄膜.Raman光谱实验结果表明:在500℃下退火处理,相同时间内H2气氛中a-Si结晶程度最好,空气气氛中结晶程度最差.这是因为高温H2退火过程中,高活性H原子能将弱的Si-Si键破坏,并与之反应形成强Si-Si键,使得薄膜结构更加稳定有序,同时能加速薄膜中氧的外扩散,促使薄膜晶化. 相似文献
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以玻璃为衬底,室温条件下采用直流磁控溅射技术制备了Glass/Al/a-Si样品.在H2,N2和空气3种不同气氛中进行了退火处理.分别采用XRD,Raman光谱和SEM研究了退火气氛对a-Si薄膜销诱导晶化(AIC)过程的影响.XRD实验结果表明:a-Si薄膜在H2气氛中400℃下经过90min的退火处理就能得到结晶较好的poly-si薄膜.Raman光谱实验结果表明:在500℃下退火处理,相同时间内H2气氛中a-Si结晶程度最好,空气气氛中结晶程度最差.这是因为高温H2退火过程中,高活性H原子能将弱的Si-Si键破坏,并与之反应形成强Si-Si键,使得薄膜结构更加稳定有序,同时能加速薄膜中氧的外扩散,促使薄膜晶化. 相似文献
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R. W. Balluffi 《Journal of Electronic Materials》1992,21(1):527-553
In recent years it has become well established that fast diffusion along grain boundaries plays a key role in many important
metallurgical processes including cases where net mass is transported along boundaries which act as sources and/or sinks for
the fluxes of atoms. In addition, considerable advances have been made in understanding grain boundary structure, and new
techniques have become available for studying kinetic phenomena in grain boundaries. This lecture will attempt to review our
current knowledge of the atomistic mechanisms responsible for these grain boundary diffusion phenomena. Relevant aspects of
the structure of grain boundaries and the point and line defects which may exist in grain boundaries are described first.
The important experimental observations are then discussed. Diffusion models are then taken up, and it is concluded that the
atomic migration occurs by a point defect exchange mechanism which, in at least the vast majority of boundaries in simple
metals, most likely involves grain boundary vacancies. The grain boundary sources and/or sinks required to support divergences
in the atomic (vacancy) fluxes are grain boundary dislocations. Phenomena therefore occur which resemblethe Kirkendall Effect
in the bulk lattice in certain respects. Additional topics are discussed which include effects of boundary structure on boundary
diffusion and the question of whether or not boundary diffusion is faster along migrating than stationary boundaries. 相似文献
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R. M. Langford M. J. Lee S. W. Wright C. P. Judge R. J. Chater T. J. Tate 《Journal of Electronic Materials》2001,30(8):925-930
The diffusion of oxygen into SiO2 encapsulated polycrystalline CdSe films and the diffusion of indium into polycrystalline CdSe films have been investigated
over the temperature range 350 C to 500 C using SIMS. The oxygen profiles in the SiO2 indicated that both isotopic oxygen exchange and the diffusion of molecular oxygen along short circuit paths were occurring
with activation energies of 1.1 eV and 0.66 eV, respectively. The activation energies determined for the diffusion of the
oxygen and indium in the grains (0.39 eV and 0.10 eV, respectively) were smaller than the values determined for the diffusion
in the grain boundaries (0.70 eV and 0.78 eV, respectively), and was attributed to impurities and intrinsic defects accumulating
at the grain boundaries. 相似文献
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《Electron Devices, IEEE Transactions on》1982,29(2):225-236
The current components associated with the grain boundaries of diffused p/n junction polysilicon solar cells made on n- and p-type Wacker substrates are analyzed and experimentally identified. New electrical methods for determining the presence or absence of preferential diffusion along the grain boundaries and for determining the average doping density of preferentially diffused regions along the grain boundaries are described. For p-type substrates, these methods revealed preferential phosphorus diffusion along grain boundaries; no preferential boron diffusion along grain boundaries was observed. The recombination current components were analyzed for the cells in which preferential diffusion occurred. The analysis shows that the dominant current component at small bias levels (0-300 mV) is the recombination current at the grain boundaries within the p/n junction space-charge region. At higher bias levels (V simeq V_{OC} simeq 500-600 mV), both this current component and the current component due to recombination at that part of the grain boundary below the preferentially diffused region are important. The grain-boundary shunt resistance does not contribute a significant current component. It is shown that the preferential diffusion makes negligible the recombination current injected into the sidewall of the preferentially diffused region. This is consistent with a model in which the phosphorus diffusion significantly lowers the surface recombination velocity at the grain boundaries and in which the retarding built-in electric field further decreases the recombination current. 相似文献
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At low temperatures, electromigration in polycrystalline Al thin-film conductors has been considered to occur predominantly
along grain boundaries. As conductor widths decrease below the average grain size, however, other transport mechanisms will
become important. Here we examine electromigration transport mechanisms in narrow AlSiCu conductors in the temperature range
190 to 290°C using the stripe drift technique. For conductors with widths between 0.9 and 2.75 μm both the absolute values
of the drift velocity and the activation energy for drift are consistent with a lattice diffusion mechanism. Over this linewidth
range the Al microstructure ranges from near-bamboo to approximately 20 μm long polycrystalline segments. The independence
of the drift data from the linewidth shows that steady state transport is controlled by the bamboo regions of the conductors,
which results from the slower rate of diffusion of Al through the lattice compared to along grain boundaries. 相似文献
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《Electron Device Letters, IEEE》1986,7(3):193-195
The fabrication procedure of the SOI/SOI/bulk-Si triple-level structure is developed by using the improved selective laser recrystallization technique and MOS LSI technology. The enlarged crystal stripes sandwiched by straight grain boundaries are produced on the planarized insulating film which overlies the device structure in bulk-Si, and also SOI/bulk-Si double-layered structure. The basic characteristics of MOSFET's in a triple-level structure are evaluated. 相似文献
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L. O. Olimov 《Semiconductors》2010,44(5):602-604
The adsorption of alkali metals and their effect on the electronic properties of grain boundaries in bulk of polycrystalline
silicon has been studied experimentally. The results obtained show that the potential barrier grows during diffusion and adsorption
of alkali metal atoms along grain boundaries. 相似文献
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Impact of Al in Cu alloy interconnects on electro and stress migration reliabilities 总被引:1,自引:0,他引:1
Kazuyoshi Maekawa Kenichi Mori Kazuhito Honda Koyu Asai Masayuki Kojima 《Microelectronic Engineering》2008,85(10):2137-2141
The reliability of Cu interconnects was successfully improved by applying a CuAl alloy seed. However, the effect of additive Al on the reliability is not fully understood. In order to reveal the reliability improvement mechanism, Cu films using CuAl alloy seed were investigated in detail. As stress induced voiding (SIV) as well as electromigration is caused by migration of vacancies and/or Cu atoms, the measured activation energy value of electromigration using CuAl indicates that the fast diffusion paths are Cu grain boundaries. The analysis using high lateral resolution scanning type secondary ion mass spectrometry (nano-SIMS) clarifies that additive Al in ECP-Cu film is mainly localized at grain boundaries. Furthermore, positron annihilation was used to probe vacancy-type defects in Cu films. The CuAl films before recrystallization contain larger and higher density vacancy-type defects. Whereas, the recrystallized CuAl films after annealing above 250 °C contain smaller and lower density defects. Furthermore, CuAl films with annealing above 350 °C contain less Al inside the grains. These results represent that Al atoms in Cu films with annealing above 350 °C are exhausted from inside grains to the grain boundaries, and the spewed Al atoms existing at Cu grain boundary effectively prevents the diffusion of Cu and/or vacancies. 相似文献
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L. O. Olimov 《Semiconductors》2012,46(7):898-900
The effect of alkali metals on carrier drift from grain boundaries to a polycrystalline silicon surface is experimentally studied. The results obtained show that an increase in the dopant concentration during the diffusion, desorption, and adsorption of alkali metals along grain boundaries leads to an increase in the potential barrier. 相似文献
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《Electron Device Letters, IEEE》1983,4(10):344-346
Our previous model for the effects of grain boundaries on the strong-inversion (linear region) conductance of silicon-on-insulator (SOI) MOSFET's is extended to account for moderate inversion. The extension, which is supported by measurements of laser-recrystallized devices, predicts a nearly exponential dependence for the conductance on the (front) gate voltage that is controlled by the grain boundaries. 相似文献