ZnS溅射功率对Cu2ZnSnS4薄膜附着性及太阳电池性能的影响

采用不同ZnS溅射功率,在钠钙玻璃(SLG)衬底上依次溅射Mo、ZnS、SnS及Cu,退火后制备出Cu_2ZnSnS_4(CZTS)薄膜。研究了溅射功率(50～140W)对ZnS薄膜和CZTS薄膜的微观形貌、微结构以及附着性的影响。结果表明,不同功率溅射的ZnS薄膜为(008)择优取向的纤锌矿六方晶系结构;功率较低时,ZnS薄膜结晶质量较差;随着功率从50W增加到140W,ZnS薄膜内的压应力增加了一个数量级;ZnS溅射功率低于80W或高于110W时,退火后的CZTS薄膜发生龟裂甚至脱落;ZnS溅射功率在80～110W时,退火后CZTS薄膜表面均匀平整;110W溅射后的CZTS薄膜出现较多的孔洞和二次相。采用80W功率溅射ZnS薄膜制备的CZTS/CdS太阳电池,开路电压达到572mV,短路电流密度为14.23mA/cm~2,光电转换效率为3.34%。     

溅射SmCo基永磁薄膜的结构和磁性能研究

以Sm(Co0.62Fe0.25Cu0.1Zr0.03)7.5合金为靶材,采用磁控溅射工艺在单晶Si基片上沉积了SmCo基永磁薄膜。研究了溅射工艺参数对薄膜的晶体结构、微观结构和磁性能的影响。结果表明:溅射气压和溅射功率的改变引起了永磁相变,这主要依赖于溅射工艺条件对薄膜Sm含量的影响。高的溅射压强和溅射功率都会引起薄膜晶粒的粗大化和薄膜表面的粗糙化。薄膜的晶体结构和微观结构随溅射参数的变化决定了薄膜的面内磁学行为。当溅射压强为0.3 Pa和溅射功率为5.1 W/cm2时,制备的退火态SmCo基薄膜为TbCu7单相晶体结构,其面内永磁性能良好。     

PET纤维基AZO透明导电薄膜溅射工艺参数的优化

室温下,结合正交实验表,用射频磁控溅射在涤纶(PET)非织造布基材上生长AZO(Al2O3:ZnO)纳米结构薄膜.采用四探针测量仪测试AZO薄膜的方块电阻,用原子力显微镜(AFM)分析薄膜微结构;通过正交分析法对实验L9(33)AZO薄膜的性能指标进行分析.实验结果表明:溅射厚度对AZO薄膜导电性能起主导作用,其次为氩气压强和溅射功率;同时,得出制备AZO薄膜的最佳工艺为:溅射功率150W、厚度100m和气压0.2Pa,该参数下样品的方块电阻为1.633×103Ω,AZO纳米颗粒的平均直径约为69.4nm.     

Mg2Si薄膜的磁控溅射制备及表征

采用直流磁控溅射的方法在Si(100)衬底上制备了Mg2Si外延半导体薄膜。通过XRD和FESEM对Mg2Si薄膜的晶体结构和表面形貌进行了表征,分析了溅射功率对Mg2Si薄膜制备的影响,得到了Mg2Si薄膜在不同溅射功率下的外延生长特性。结果表明,在Si(100)衬底上,Mg2Si薄膜具有(220)的择优生长特性,并且在50~80W的溅射功率范围内,随着溅射功率的增加,Mg2Si外延薄膜的衍射峰强度逐渐增强。     

ZnO∶Nb透明导电薄膜的制备及光电特性研究

采用直流磁控溅射法在玻璃衬底上沉积铌掺杂氧化锌(NZO)透明导电薄膜。通过X射线衍射(XRD)、扫描电镜(SEM)以及透射光谱等测试研究了溅射功率对薄膜结构、形貌以及光电性能的影响。实验结果表明NZO薄膜是多晶膜,具有ZnO的六角纤锌矿结构,最佳取向为(002)方向。溅射功率从40W增加到80W时,薄膜的电阻率迅速下降;功率超过80W时,电阻率趋于平稳。在溅射功率为100W时,电阻率具有最小值5.89×10-4Ω.cm,光学带隙具有最大值3.395eV。实验制备的NZO薄膜附着性能良好,在可见光范围内的平均透过率均超过86.6%。     

磁控溅射法制备NiZnCo铁氧体磁性薄膜的工艺研究

采用磁控溅射在硅晶基体上制备NiZnCo铁氧体磁性薄膜,研究了溅射功率对溅射(沉积)速率和微观形貌的影响规律:随着溅射功率由80W增大到150W,薄膜的沉积速率增大;薄膜却由整齐均匀分布的小颗粒状向片状结构变化,分布也不均匀,晶粒明显长大.由此确定最佳溅射功率为120 W,薄膜的微观形貌最理想,溅射(沉积)速率也很快.     

溅射功率对InZnO薄膜晶体管电学性能的影响研究北大核心CSCD

采用射频磁控溅射法,在室温下Si/SiO_(2)衬底上制备InZnO薄膜晶体管,并研究不同溅射功率(25,50,75和100 W)对InZnO薄膜晶体管电学性能的影响。XRD表征结果表明,不同溅射功率制备的InZnO薄膜均出现晶面为(002)面的多晶态结构。通过电学特性研究发现,当溅射功率为50 W时,电流的开关比为3×10^(7),场效应迁移率为14.8 cm^(2)V^(-1)s^(-1),阈值电压为0.82 V,亚阈值摆幅为0.38 V decade^(-1),界面缺陷态密度为1.1×10^(12)cm^(-2)eV^(-1)等获得最佳器件参数。这是因为功率50 W时用原子力显微镜测得InZnO薄膜表面粗糙度为0.86 nm,说明薄膜的表面比较平滑,表面缺陷密度较少,使InZnO薄膜沟道层和源漏电极形成了良好的接触。此外,XPS结果表明,当溅射功率为50 W时,能够有效控制氧空位缺陷,最终有效改善和提高InZnO薄膜晶体管的电学性能。     

直流磁控溅射功率对溅射生长GZO薄膜光电性能的影响

本文采用直流磁控溅射沉积系统在玻璃基底上沉积镓掺杂氧化锌(GZO)薄膜,将溅射功率从120W调整到240W,步长为30W,研究功率变化对GZO薄膜的晶体结构、表面形貌、光学性能和电学性能的影响。结果表明,溅射功率对GZO薄膜电阻率有显著的影响。溅射功率为210W时薄膜呈现最低电阻率为3.31×10~(-4)Ω·cm,可见光波段平均光学透光率接近84%。随着溅射功率的增加,薄膜表面形貌和生长形态发生较大变化,并直接得到具有一定凸凹不平的微结构,GZO薄膜的致密性先增加后降低。     

射频磁控溅射法制备碲化铅薄膜的X射线衍射分析

采用射频磁控溅射法,在单面抛光的Si(111)衬底上制备了PbTe薄膜,利用X射线衍射法分析了溅射工艺参数如溅射功率、溅射时间、衬底温度以及退火温度对PbTe薄膜的结晶质量的影响。结果表明:在溅射功率为30W,溅射时间为10 min,衬底未加热时制备的薄膜具有最好的〈100〉方向的择优取向性;退火处理可以改善薄膜的结晶质量,并且退火温度越高,薄膜的结晶质量越好。     

磁控共溅射法制备ZrRu薄膜及其电学性能研究

扩散阻挡层的选材是Cu互连工艺研究重点之一,目前在研的阻挡层中,由两种难熔金属组成的二元合金因具有与Si反应温度高、电阻率低、结晶温度高等优点,成为一类极具应用潜力的阻挡层材料。本文通过磁控共溅射技术在p型Si单晶基底上沉积ZrRu薄膜。利用X射线光电子能谱、X射线衍射、扫描电子显微镜和四点探针测试等表征手段对ZrRu合金膜的化学特性、物相结构、微观形貌和电学性能进行表征分析。研究结果表明,随Ru溅射功率增加,Ru原子百分比增加,薄膜的沉积速率由7.74 nm·min~(-1)增加到17.99 nm·min~(-1) ,当Ru溅射功率低于35 W时,薄膜为非晶或微晶结构;当Ru溅射功率为45 W时,薄膜逐渐转化为柱状晶结构,且尺寸均匀,表明通过Ru掺杂实现了对ZrRu薄膜微观结构的调控;薄膜电阻率随Ru溅射功率增加由192.2μΩ?cm降低为53.5μΩ?cm,表现出良好的电学性能。     

Comparative studies on structural, optoelectronic and electrical properties of SILAR grown PbS thin films from acidic, neutral and alkaline cationic reaction bath

Thin films of Lead sulphide (PbS) were grown on soda lime glass substrate by Successive Ionic Layer Adsorption and Reaction method from acidic, neutral and alkaline cationic precursor reaction bath by keeping the pH of the anionic precursor invariant. The structural and morphological aspects of the as prepared samples were investigated using XRD and SEM results. The as-prepared samples were polycrystalline with nanometer sized grains and identified as galena type cubic structure. The values of average crystallite size were found to be in the range 22–30?nm. The SEM micrographs show variations in morphology. Optical studies revealed the existence of both direct and indirect band gap with values in the range of 1.65–1.98 and 0.61–0.90?eV respectively. The room temperature conductivity of the PbS thin films were in the range 1.19?×?10^?8–5.92?×?10^?8?Ω?cm^?1. The optical band gap energy has inverse relation with grain size and electrical conductivity is closely related to structural parameters like grain size, crystallinity and micro strain. The estimated lattice parameter, grain size, optical band gaps, solid state and electrical properties were correlated with pH of the cationic solution. In this work, we establish that the pH of the cationic precursor media has colossal effect on the structural, morphological, optoelectronic, solid-state and electrical properties of PbS thin films.     

Nitrogen-incorporation induced changes in the microstructure of nanocrystalline WO3 thin films

Nitrogen incorporated tungsten oxide (WO₃) films were grown by reactive magnetron sputter-deposition by varying the nitrogen content in the reactive gas mixture keeping the deposition temperature fixed at 400 °C. The crystal structure, surface morphology, chemical composition, and electrical resistivity of nitrogen doped WO₃ films were evaluated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and electrical conductivity measurements. The results indicate that the nitrogen-incorporation induced changes in the microstructure and electrical properties of WO₃ films are significant. XRD measurements coupled with SEM analysis indicate that the increasing nitrogen content decreases the grain size and crystal quality. The nitrogen concentration increases from 0 at.% to 1.35 at.% with increasing nitrogen flow rate from 0 to 20 sccm. The corresponding dc electrical conductivity of the films had shown a decreasing trend with increasing nitrogen content.     

CuO掺杂对WO_3压敏电阻微结构和电学性能的影响

研究了CuO掺杂对WO_3压敏电阻微结构和电学行为的影响,样品采用传统的陶瓷工艺制备.微结构通过扫描电子显微镜(SEM)观察,相结构和成分借助于X射线衍射(XRD)和能谱(EDS)进行分析.结果表明,微量的CuO掺杂能够促进WO_3陶瓷的致密化和晶粒生长.根据I-V特性测量结果,0.2%(摩尔分数)CuO掺杂的WO_3陶瓷具有线性伏安特性和极小的电阻率.CuO含量的继续增加使样品的非线性电学行为和电阻率又获得恢复,这是因为偏析于晶界处的CuO与两侧的晶粒形成了n-p-n型的双肖特基势垒.     

掺杂对Y—TZP陶瓷结构和电性能的影响

本文研究了掺杂对钇稳定四方ZrO_2(YTZP)陶瓷材料结构和电性能的影响。通过密度测定,SEM和电性能测量分析可知:掺杂的Y-TZP材料晶粒呈不规则多边形且分布均匀,晶粒平均尺寸在0.4μm左右。掺杂材料的电导激活能均小于未掺杂YTZP材料的电导激活能;材料的晶粒电阻率随掺杂种类和浓度的变化不大,而掺杂Fe_2O_3和SiO_2的Y-TZP陶瓷材料则呈现较小的晶界电阻率.     

Grain size control in ITO targets and its effect on electrical and optical properties of deposited ITO films

Tin-doped indium oxide (ITO) ceramic targets with three types of grain size (<10, 10–20 and >20 μm) were prepared by controlling sintering process. It is found that all targets show polycrystalline structure and a rapid heating and short holding time contributes to refining grain size. The ITO films were deposited using these ITO targets with three types of grain sizes under dc and rf mode. The effects of grain size on the structural, electrical and optical properties of the as-deposited films were systematically investigated. The results indicate that all ITO films are the (222) preferred orientation, and the surface grain morphologies are round (dc mode) and triangular (rf mode). The sheet resistance, transmittance and uniformity of the ITO films are significantly impacted by the grain size. The small grain size (<10 μm) contributes to improving the uniformity of electrical and optical properties. The optimal uniformity of sheet resistance under dc and rf mode is about 13 and 10 %, respectively.     

磁控溅射沉积Cu-W薄膜的特征及热处理的影响

采用磁控共溅射法制备含钨1.51%~14.20%(原子分数,下同)的Cu-W合金薄膜,并用EDX、XRD、SEM、显微硬度仪和电阻仪研究了其成分、结构及性能。结果表明,添加W可显著细化Cu-W薄膜基体相晶粒,晶粒尺寸随W含量的增加而减小,Cu-W薄膜呈纳米晶结构。Cu-W薄膜中存在W在Cu中形成的fcc Cu(W)非平衡亚稳过饱和固溶体,固溶度随W含量的增加而提高,最大值为10.65%。与纯Cu膜对比发现,薄膜的显微硬度和电阻率总体上随W含量的增加而显著增大。经200℃、400℃及650℃热处理1h后,Cu-W薄膜基体相晶粒长大,EDX分析显示晶界处出现富W第二相;薄膜显微硬度降低,电阻率下降,降幅与退火温度呈正相关。添加W引起的晶粒细化效应以及退火中基体相晶粒度增大分别是Cu-W薄膜微观结构和性能形成及演变的主要原因。     

Sintering of Calcia-Stabilized Zirconia an Extended Arc Thermal Plasma Reactor

Commercial-grade zirconia powder (average, 10-m particle size) compacts with 5 wt% of calcia have been sintered (batchwise) in a short time using an indigenously made low-cost extended arc thermal plasma heating (EATPH) system with varying plasma reactor operating parameters such as plasma power, plasmagen gas flow rate, and sintering time. XRD, SEM, laser particle size analyzer, and density studies were carried out to evaluate the structural, morphological, and physical properties of the sintered samples. It is observed from the above studies that the sintered products are fully monophasic and stabilized to the cubic system with 92% of the theoretical density in 15 min. A uniform grain size with no runaway grain growth occurred during sintering by our EATPH technique. The pore-grain structure mechanism in relation to the grain growth and density of the materials is discussed.     

Low Resistance Polycrystalline Diamond Thin Films Deposited by Hot Filament Chemical Vapour Deposition

Polycrystalline diamond thin films with outgrowing diamond (OGD) grains were deposited onto silicon wafers using a hydrocarbon gas (CH4) highly diluted with H2 at low pressure in a hot filament chemical vapour deposition (HFCVD) reactor with a range of gas flow rates. X-ray diffraction (XRD) and SEM showed polycrystalline diamond structure with a random orientation. Polycrystalline diamond films with various textures were grown and (111) facets were dominant with sharp grain boundaries. Outgrowth was observed in flowerish character at high gas flow rates. Isolated single crystals with little openings appeared at various stages at low gas flow rates. Thus, changing gas flow rates had a beneficial influence on the grain size, growth rate and electrical resistivity. CVD diamond films gave an excellent performance for medium film thickness with relatively low electrical resistivity and making them potentially useful in many industrial applications.     

一种Carbonado型结构的爆炸纳米多晶金刚石

介绍了Carbonado型结构的爆炸纳米多晶金刚石的爆炸技术以及计算压力与温度的理论方法,指出计算压力的"均相分布"理论不被实验所证实.通过扫描电镜、原子力显微镜和透射电镜表征了这种金刚石的形貌特征,并将Scherrer公式与X射线小角度散射法的测试结果与显微镜下的图像相对照,确定了金刚石的粒度为50nm(30～70nm).通过100万倍的透射电镜分析,确认在扫描电镜和原子力显微镜下看到的颗粒是由3.5～6.0nm的小晶粒以不饱和键聚晶而成.在一次特殊设计的实验中,首次发现过去从未有人提出过的多晶金刚石与水可在一定时间内保持的自悬浮胶体,并作出初步解释.     

Effect of process parameters on grain structure formation during VAR of INCONEL alloy 718

The development of grain structure during Vacuum Arc Remelting (VAR) of INCONEL¹ alloy 718, a nickel-based superalloy, is complex depending both on compositional variations and a range of process parameters. A multiscale model is presented which combines a macroscopic solution of the heat transfer, fluid flow and electromagnetism with a mesoscopic model of grain nucleation and growth. The model was used to investigate the influence of variations in process control parameters upon the macroscopic molten pool size and shape, together with the predicted grain structure. Simulations of structures produced for variations in melt rate, arc power and arc focus (both thermal and electrical) were compared with observations from instrumented and characterized plant-trials for steady state melting conditions; good agreement was achieved.