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1.
用区熔技术改善多晶硅薄膜颗粒硅带衬底的质量   总被引:1,自引:1,他引:0  
以颗粒硅带为衬底,通过化学气相沉积法制备多晶硅薄膜作为太阳电池的活性层.为了改善硅带衬底的质量,引入区熔再结晶的方法,期望将其表面平整度及结晶质量进一步提高,进而改善以其为衬底的多晶硅薄膜质量.借助台阶仪、X射线衍射(XRD)、扫描电镜(SEM)等手段对颗粒硅带及多晶硅薄膜进行了表面轮廓、结晶质量和微观形貌的表征.结果表明:区熔后的颗粒硅带表面平整度得到了较好的改善;表面具有[311]择优方向的硅带区熔后都倾向[111]择优;在区熔硅带衬底上沉积的多晶硅薄膜晶粒尺寸在100μm以上,但暂无明显证据证明区熔对薄膜结晶质量有显著提高.  相似文献   

2.
通过金属氧化物化学气相沉积(MOCVD)方法在2.5μm×1.6μm×0.5μm圆锥形图形化蓝宝石衬底(CPSS)和没有图形化平面蓝宝石衬底(uss)上生长GaN外延膜.高分辨率X射线衍射仪(HRXRD)测试结果表明,生长在CPSS上GaN的刃位错的密度比生长在USS上GaN的刃位错密度低得多;从透射电子显微镜(TEM)观察,CPSS可有效地减小GaN外延膜中的线位错密度;拉曼散射谱显示通过CPSS可有效地减小GaN外延膜中的残余应力;比较两种外延膜中的光致发光谱(PL),能从生长在CPSS上GaN外延膜中观察到强而尖的带边发射.以上结果表明:生长在CPSS上GaN外延膜的质量高于生长在USS上GaN外延膜的质量.  相似文献   

3.
运用能量极小原理,研究了磁性薄膜-非磁衬底悬臂梁系统的弯曲问题,着重分析了悬臂梁体系的中平面、磁膜内应力和应变与构成悬臂梁的两种材料的几何参数和物理参数的关系,给出了这些参数对磁膜.衬底悬臂梁系统弯曲特性的影响.结果表明,由于磁致伸缩效应是各向异性膨胀,体系的中平面在一般情况下是各向异性的.随着磁膜厚度的增加,中平面迅速下降,同时衬底对磁膜的束缚减小,从而释放了磁膜内应力,即应力减小;而磁膜应变随膜厚增加而增加.材料泊松比对垂直于磁化方向的应力和应变以及中平面的影响较大.但是,对磁化方向的应力、应变中平面的影响很小,这一性质来源于磁化方向上磁膜主动伸缩效应.  相似文献   

4.
利用第一性原理研究了氧化亚氮(N2O)分子单层膜在Cu(100)表面吸附的原子结构。CASTEP计算表明当覆盖度为0.5ML时,N2O分子单层膜在虚拟Cu(100)表面稳定。当N2O分子自组装单层膜吸附在Cu(100)衬底上时,最稳定的吸附位是顶位,此时吸附高度是1.98A,分子与衬底法线之间的夹角是54度,而分子内部的键角是174度。计算结果与实验数据吻合。  相似文献   

5.
本文选C2分子和Ar离子作为沉积源和辅助沉积粒子,采用分子动力学(MD)方法在Si(111)面上模拟研究了离子束辅助沉积(IBAD)类金刚石(DLC)膜的物理过程.重点讨论了C2分子和Ar离子的入射能量及到达比(Ar/C)对平均密度和sp^3键含量的影响,并与Si(001)-(2×1)表面生长类金刚石膜的结果进行比较.结果表明,到达比和入射能的改变,对薄膜结构的影响不同;Si(111)面上生长类金刚石膜,薄膜在衬底的附着力更强.  相似文献   

6.
a-Si:H薄膜固相晶化法制备大晶粒多晶硅薄膜   总被引:5,自引:0,他引:5  
用等离子体化学气相沉积(PCVD)法制备:a-Si:N薄膜材料(衬底温度20O℃~350℃),用固相晶化法(SPC)获得多晶硅薄膜(退火温度500℃~650℃),用X射线衍射法测得平均晶粒尺寸依赖于退火温度和沉积条件,随着沉积温度的降低需要较高的退火温度,用SEM观测形貌测得平均晶粒大小为1,0~1,5μm  相似文献   

7.
利用有限元方法模拟了图形化Si衬底上外延Ge薄膜的热失配应变,研究了薄膜内部以及表面的应变分布情况,分析了应变与薄膜厚度、衬底尺寸的变化关系.结果表明,热失配应变在异质结构的界面处最大,沿外延层生长方向递减;在薄膜表面,中心区域应变最大,由中心到边缘逐渐减小,边缘发生突变,急剧减小;不同的膜厚下,薄膜表面应变分布规律相同,并且薄膜越厚,应变越小;图形衬底单元的尺寸对薄膜应变有较大的影响,当衬底厚度在6μm以内,宽度在10μm以内时,更有利于薄膜应变的释放.  相似文献   

8.
采用扫描电子显微镜和光学显微镜等方法,对在不锈钢衬底上固化后环氧树脂胶的显微结构进行了测量与分析.结果表明:1)环氧树脂样品中存在一定的宏观(0.1mm)不均匀,既存在无色透明的区域,也存在半透明乳白色区域.在乳白色区域中,还存在白色斑点.无色透明区域在约10μm尺度以上,空间均匀性较好;在约10μm尺度以下,出现空间不均匀性.半透明乳白色区域中斑点大小为1μm量级的近圆形区域.2)边缘处的环氧树脂胶厚度逐渐变薄,表明未固化的环氧树脂胶与不锈钢衬底之间即使达到μm级仍然是浸润接触.在样品中没有观察到裂纹,样品和衬底之间也未观察到缝隙.边缘与衬底接触部分形成较为均匀、平行于衬底表面、厚度约0.5μm的空间层状结构.  相似文献   

9.
报道了TiNi薄膜的聚焦离子束刻蚀特征及刻蚀后的表面形貌.测量结果表明薄膜的表面粗糙度随刻蚀深度呈非线性变化,当刻蚀深度等于0.1μm时,表面粗糙度为最小(5.26nm,刻蚀前为14.88nm);刻蚀深度小于0.1μm时,表面粗糙度随刻蚀深度的增大而减小;当刻蚀深度大于0.1μm时表面粗糙度随刻蚀深度增大而增大,其原因是刻蚀深度大于0.1μm后表面出现了清晰的周期性条纹结构.此外,表面粗糙度随聚焦离子束流的增大而减小,当离子束流为2.5nA时,表面粗糙度从刻蚀前的14.88nm减小到4.67nm.  相似文献   

10.
研究了在离体环境下,蔗糖、硼酸、2,4-D、钙离子分别对紫叶小檗花粉萌发及生长的影响。结果表明,蔗糖质量分数为10%时,紫叶小檗花粉管长度达到最长,为1 500μm;硼酸质量浓度为100 mg.L-1时,花粉管长度达到最长,为640μm;2,4-D质量浓度为3 mg.L-1时,花粉管长度达到最长,为340μm;CaC l2.2H2O质量浓度为200 mg.L-1时,花粉管长度达到最长,为655μm。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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