预非晶化离子注入对硅p^＋n结构性能的影响

用Ｓｉ＾＋／Ｂ、Ａｒ＾＋／Ｂ＾＋双注入结合快速退火技术制备出了较浅的ｐ＾＋ｎ结,用四探针法、扩展电阻法、背散射沟道谱、二次离子质谱等测试分析手段研究了Ｓｉ＾＋或Ａｒ＾＋预蜚 晶人离子注入的作用。结果表明,适当条件的Ｓｉ＾＋／Ｂ＾＋双注入制备 高硼原子电激活率的Ｐ＾＋薄层且电性能优良,残留二次缺陷少,ｐ＾＋ｎ结二极管反忖电流仅２．０ｎＡ／ｃｍ＾２（－１．４Ｖ）;而Ａｒ＾＋主虽然也能抑制硼原子注入沟道     

高分子p—n异质结太阳电池的研究

用合成的十二烷基苯磺酸（ＤＢＳＡ）掺杂的聚苯胺（ＰＡｎ）导电材料和Ｂｅｉ染料组合，采用涂覆技术，研制成ＳｎＯ２／ＰＡｎ膜／Ｂｅｉ染料薄层／Ａｌ栅电极结构和Ａｌ／ＰＡｎ导电基片／Ｂｅｉ染料薄层／Ａｌ栅电极结构的ｐ－ｎ异质结太阳电池，测定了该电池的光电效应和伏安特性，在４．７２ｍＷ／ｃｍ＾２的氙灯照射下，开路电压Ｖｏｃ达４００ｍＶ短路电流Ｉｓｃ为１０μＡ，填充因子可达５７．４％，光电转换效率为０．０９     

Ga－Al－As－Si系统中Si的两性掺杂行为的研究

对Ｓｉ在电液相外延Ｇａ－Ａｌ－Ａｓ－Ｓｉ系统中的两性掺杂行为进行了研究。提出了一种恒温生长Ｇａ＿（１－ｘ）Ａｌ＿ｘＡｓ：Ｓｉｐ－ｎ结的新方法，对这种ｐ－ｎ结的成因作了定性的解释，并对这种ｐ－ｎ结的电特性加以观察。     

代位原子在Fe3Al亚点阵中的占位与合金的塑性

采用中子衍射法测定了Ｃｒ、Ｍｏ、Ｔｉ、Ｎｉ、Ｍｎ、Ｓｉ等代位原子在ＤＯ３结构Ｆｅ３Ａｌ亚点阵中的原子占位，并从解离能角度探讨了原子对之间的相互作用及合金室温塑性的影响，结果表明：Ｃｒ、ＭＯ、Ｔｉ都占据了Ａｌ原子的次近邻位置，替代Ｆｅ原子；Ｎｉ、Ｍｎ占据Ａｌ原子的最近邻位置，（Ｓｉ＋Ａ）当量成分以内的Ｓｉ原子替代占据Ａｌ原子的位置，由于Ａｌ－Ｃｒ原子对的结合能低于Ｆｅ－Ａｌ，ＡＬ－Ｍｏ用Ａｌ－Ｔｉ对     

DRS／SDS／NF体系中合成聚丁二烯 胶乳的粒子形态的研究

在以岐化松香皂（ Ｄ Ｒ Ｓ）、十二烷基硫酸钠（ Ｓ Ｄ Ｓ）和间次甲基萘磺酸盐（ Ｎ Ｆ）组成三元复合乳化剂体系中,研究了 Ｓ Ｄ Ｓ／ Ｄ Ｒ Ｓ、 Ｎ Ｆ／ Ｄ Ｒ Ｓ、碳酸盐（ Ｃａ）、丁二烯（ Ｂｄ）中二聚体（ Ｄｉ）及后处理工艺对 Ａ Ｂ Ｓ用聚丁二烯胶乳（ Ｐ Ｂ Ｌ）的粒子形态等的影响。结果表明, Ｓ Ｄ Ｓ／ Ｄ Ｒ Ｓ增加, Ｐ Ｂ Ｌ平均粒径（ Ｄｐ）和粒子分散度（ Ｐｏｌｙ ｄ）均减小,且粒子形态趋于规整。 Ｎ Ｆ／ Ｄ Ｒ Ｓ增大使 Ｒｐ 减小,但可以较好地改善 Ｐ Ｂ Ｌ的稳定性。［ Ｃａ］＞ １．２％ , Ｄｐ 显著增大,但使粒子间粘连加重,规整性变差。［ Ｄｉ］增加使 Ｐ Ｂ Ｌ粒子分布变宽,形态变差。在 １００ ｒ／ｍ ｉｎ 转速下处理 Ｐ Ｂ Ｌ ４ ｈ 可以使 Ｄｐ 增大和 Ｐｏｌｙ ｄ 减少,有利单分散性大粒径的 Ｐ Ｂ Ｌ合成。     

配对材料对Al-10Si/SiC_p复合材料滑动磨擦性能的影响

通过对Ａｌ－１０Ｓｉ／ＳｉＣｐ－４０Ｃｒ、Ａｌ－１０Ｓｉ／ＳｉＣｐ－Ｈ６２、Ａｌ－１０Ｓｉ／ＳｉＣｐ—Ａｌ－１０Ｓｉ／ＳｉＣｐ三对摩擦副的研究，发现配对材料对复合材料的抗磨损性能影响很大。结果表明，在试验条件下４０Ｃｒ钢适合与该铝基复合材料配对使用，而黄铜和该材料配对使用，则会大大降低复合材料耐磨损性能。另外，在较低载荷条件下，Ａｌ－１０Ｓｉ／ＳｉＣｐ自配对磨损率很低，亦能自配对使用。     

非晶态铁电薄膜的铁电相转变

用ＡｒＦ脉冲激光在Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上合成了非晶态ＳｒＢｉ２Ｔａ２Ｏ９铁电薄膜,研究了铁电相转变。采用常规热退火、激光诱导和低温高压水热法使非晶态ＳＢＴ薄膜发生铁电相转变。     

PECVD方法制备SnO2气敏薄膜的电子显微镜研究

通过ＳＥＭ、ＴＥＭ研究了ＰＥＣＶＤ方法制备的ＳｎＯ＿２薄膜的显微结构，讨论了沉积速率与颗粒大小的关系；在Ｓｉ、陶瓷和ＫＢｒ３种不同衬底上沉积的ＳｎＯ＿２薄膜的差异以及退火对ＳｎＯ＿２膜结晶状态的影响。结果表明，ＰＥＣＶＤ方法制备的ＳｎＯ＿２薄膜是非晶态，具有柱状结构。退火使非晶ＳｎＯ＿２膜向着多晶方向转化，演化过程为：非晶大颗粒→超微粒多晶→晶粒长大。     

形变对Fe—30Mn—6Si基合金形状记忆效应的影响及其机理研究

本文用膨胀法比较了Ｆｅ－３０Ｍｎ－６Ｓｉ合金在拉伸应变下纵向（沿拉伸方向）和横向（垂直拉伸方向）恢复率的不同；研究了预应变对纵向恢复量，恢复率以及Ａｓ，Ａｆ的影响；还用一个大应变量下的样品在Ａｓ和Ａｆ范围内的不同区间进行了加热和冷却循环试验，得到了一些很有意义的信息。用正电子湮灭方法研究了Ｆｅ－３０Ｍｎ－６Ｓｉ，Ｆ３－３０Ｍｎ－６Ｓｉ－５Ｃｒ合金时效和非时效样品位伸预应变量对合金中的缺陷量，缺陷密     

分子束外延生长GaAs中δ掺杂研究

利用二次离子质谱（ＳＩＭＳ）和电化学剖面Ｃ－Ｖ方法研究了生长温度对ＧａＡｓ中理想Ｓｉδ掺杂的结构的偏离和掺杂原子电微活效率的影响。实验发现，外延生长Ｓｉδ掺杂，ＧａＡｓ时，随着生长温度的升高，Ｓｉ掺杂分布ＳＩＭＳ峰非对称展宽。表面分凝作用加强，但不影响Ｓｉ原子扩散。另外，Ｓｉ施主电激活效率随着生长温度的提高而增大。     

Effects of annealing on the damage morphologies in BF 2 + ion implanted (1 0 0) silicon

The effects of annealing on the damage morphologies and impurity redistributions in BF ₂ ⁺ ion implanted (1 0 0) silicon were studied using secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM) and Rutherford backscattering (RBS) ion beam channelling technique. An amorphized silicon layer and a heavily-damaged crystal layer containing a high density of point-defect clusters, are formed on the silicon wafer by the ion implantation. SIMS depth profiles of both boron and fluorine are almost Gaussian distribution. Both furnace annealing and rapid thermal annealing cause recrystallization of the amorphized layer and formation of dislocation loop bands out of the point defects. SIMS depth profiles for both impurities show anomalous double peaks at the same depths. These facts suggest that the primary peak is due to the peak of the Gaussian distribution and the secondary peak due to the gettering effects of residual dislocation loop band.     

硅纳米晶微观结构缺陷的高分辨电子显微学研究

利用离子注入结合后续高温退火的方法成功地制备出包埋在二氧化硅(SiO_2)基质中的硅纳米晶.利用透射电子显微学对所制备的硅纳米晶(离子注入浓度为3×10~(17)cm~(-2))的微观结构缺陷进行了详细的研究.通过高分辨像分析发现:较大的纳米晶(直径＞6nm)中存在很多面缺陷,主要为孪晶与层错.孪晶包括一次孪晶、二重孪晶、三重孪晶及五重孪晶.层错分为内禀和外禀两种类型,并讨论了内禀层错占多数的原因.除了面缺陷以外,还有一部分纳米晶中存在位错.     

Decrease in work function of boron ion-implanted ZnO thin films

We have fabricated boron ion-implanted ZnO thin films by ion implantation into sputtered ZnO thin films on a glass substrate. An investigation of the effects of ion doses and activation time on the electrical and optical properties of the films has been made. The electrical sheet resistance and resistivity of the implanted films are observed to increase with increasing rapid thermal annealing (RTA) time, while decreasing as the ion dose increases. Without any RTA process, the variation of the carrier density is insensitive to the ion dose. With the RTA process, however, the carrier density of the implanted films increases and approaches that of the un-implanted ZnO film as the ion dose increases. On the other hand, the carrier mobility is shown to decrease with increasing ion doses when no RTA process is applied. With the RTA process, however, there is almost no change in the mobility. We have achieved the optical transmittance as high as 87% within the visible wavelength range up to 800 nm. It is also demonstrated that the work function can be engineered by changing the ion dose during the ion implantation process. We have found that the work function decreases as the ion dose increases.     

Active doping of B in silicon nanostructures and development of a Si quantum dot solar cell

Active doping of B was observed in nanometer silicon layers confined in SiO(2) layers by secondary ion mass spectrometry (SIMS) depth profiling analysis and confirmed by Hall effect measurements. The uniformly distributed boron atoms in the B-doped silicon layers of [SiO(2) (8 nm)/B-doped Si(10 nm)](5) films turned out to be segregated into the Si/SiO(2) interfaces and the Si bulk, forming a distinct bimodal distribution by annealing at high temperature. B atoms in the Si layers were found to preferentially substitute inactive three-fold Si atoms in the grain boundaries and then substitute the four-fold Si atoms to achieve electrically active doping. As a result, active doping of B is initiated at high doping concentrations above 1.1 × 10(20) atoms cm( - 3) and high active doping of 3 × 10(20) atoms cm( - 3) could be achieved. The active doping in ultra-thin Si layers was implemented for silicon quantum dots (QDs) to realize a Si QD solar cell. A high energy-conversion efficiency of 13.4% was realized from a p-type Si QD solar cell with B concentration of 4 × 10(20) atoms cm( - 3).     

Effect of Si and He implantation in the formation of ultra shallow junctions in Si

He, Si and B implantation are successively combined in order to produce ultra shallow junctions (USJs). Si is implanted at 180 keV to create a ‘vacancy-rich’ layer. Such a layer is however followed by a deeper interstitial rich one. He implantation is performed at a dose high enough (5 × 10¹⁶ cm^− 2) to create a cavity layer in Si sample. Eventually, B is introduced by low energy ion implantation. Since cavities are known to be sinks for self-interstitials (Is), they might be able to decrease the transient enhanced diffusion (TED) of B during the dopant activation annealing in all processes investigated in this study. The samples are divided in two groups (named S1 and S2) to check the benefits of defect engineering of each implantation element. Hence, sample 1 is first implanted with He, followed by cavity formation annealing and second with B. Si implantation is performed on S2 after cavity formation, and followed by B implantation in the same condition as S1. All samples are characterized by secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM) and Hall effect measurements. Results show that, in all cases, boron TED is suppressed while working with a cavity layer created before activation annealing. This layer acts as an Is barrier. Finally, an USJ with a low junction depth (X_j = (13 ± 1) nm, determined at 10¹⁸ cm^− 3 boron level) is successfully realized.     

Electrical and optical properties of semi-insulating polycrystalline silicon thin films: the role of microstructure and doping

We have investigated the relationship between microstructure and electrical conductivity in semi-insulating polycrystalline silicon (SIPOS) with oxygen concentrations in the 2–35 at.% range and the effect of doping with boron, phosphorus, arsenic and erbium by ion implantation. SIPOS thin films are mixtures of silicon and silicon oxide phases. The chemical and morphological evolution of these phases upon annealing is emphasized. Electrical conductivity measurements are interpreted in terms of a physical model containing few free parameters related to the material microstructure. A direct extension of this model explains also the conductivity increase in SIPOS doped with elements of the third or the fifth group. In the last part of the paper, data of electroluminescence at 1.54 μm in Er-implanted SIPOS due to intra-4f transitions of the Er³⁺ ion are shown and discussed.     

Effects of the integrity of silicon thin films on the electrical characteristics of thin dielectric ONO film

Capacitors with two kinds of lower electrodes were fabricated and their effects evaluated on the electrical characteristics of oxide–nitride–oxide (ONO) film. One of the electrodes was made of amorphous silicon film chemically deposited using a gas mixture of Si2H6–PH3; the other was made of poly-Si film deposited by SiH4 decomposition and doped by As+ ion implantation. The ONO thin dielectric layer was composed of natural oxide, CVD silicon nitride and thermal oxide formed on the silicon nitride. The capacitance, the leakage current, the dielectric breakdown field and the time-dependent dielectric breakdown (TDDB) were tested to evaluate the electrical properties of the capacitors. The leakage current and the dielectric breakdown voltage showed similar values between the two capacitors, whereas the TDDB under negative bias showed a great difference. This indicates that, with respect to electrical properties, the integrity of the oxide grown on the in situ P-doped amorphous silicon is better than the oxide grown on the As+ ion-implanted poly-Si. What is more, phosphorus in the amorphous silicon did not lead to any problems with junction depth, even after post heat treatment at 950°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fabrication of ordered NiO coated Si nanowire array films as electrodes for a high performance lithium ion battery

Highly ordered NiO coated Si nanowire array films are fabricated as electrodes for a high performance lithium ion battery via depositing Ni on electroless-etched Si nanowires and subsequently annealing. The structures and morphologies of as-prepared films are characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. When the potential window versus lithium was controlled, the coated NiO can be selected to be electrochemically active to store and release Li+ ions, while highly conductive crystalline Si cores function as nothing more than a stable mechanical support and an efficient electrical conducting pathway. The hybrid nanowire array films exhibit superior cyclic stability and reversible capacity compared to that of NiO nanostructured films. Owing to the ease of large-scale fabrication and superior electrochemical performance, these hybrid nanowire array films will be promising anode materials for high performance lithium-ion batteries.     

Piezoelectric and optical properties of ZnO thin films deposited using various O<Subscript>2</Subscript>/(Ar+O<Subscript>2</Subscript>) gas ratios

In this study, ZnO thin films were fabricated on a Pt(111)/TiO_x/SiO₂/Si substrate using the RF magnetron sputtering method. Then, the effect of the crystallization orientation and microstructure on the piezoelectric and optical properties of the ZnO thin film was investigated for various O₂/(Ar+O₂) gas ratios. When the O₂/(Ar+O₂) gas ratio was 50%, the intensity of the (002) peak corresponding to the preferred orientation of the ZnO thin film was a maximum and the minimum FWHM value of 0.56° was observed. The surface roughness of the ZnO thin film measured using AFM also had a minimum value of 16.43 °C at an O₂/(Ar+O₂) gas ratio of 50%. The piezoelectric characteristics of the ZnO thin film were measured using the pneumatic loading method (PLM) and the corresponding constant had the largest value of 11.9 pC/N at an O₂/(Ar+O₂) gas ratio of 50%. The transmittance of the ZnO thin film obtained from the transmittance curve using a spectrophotometer was slightly greater than 80% in the human visible light region at an O₂/(Ar+O₂) gas ratio of 50%. By using the refractive index data obtained from the transmittance curve and the Sellmeir dispersion relation, we can also predict the refractive index at a wavelength of 400 nm. When the O₂/(Ar+O₂) gas ratio was 50%, the refractive index was 2.043 and, at other gas ratios, the corresponding refractive indices were 2.004∼2.006. The band gap energies of the ZnO thin film were 3.27∼3.33 eV depending on the O₂/(Ar+O₂) gas ratio and were little affected by the variation of the oxygen inflow volume.     

Effect of growth temperature on structural, electrical and optical properties of dual ion beam sputtered ZnO thin films

ZnO epitaxial thin films were grown on p-type Si(100) substrates by dual ion beam sputtering deposition system. The crystalline quality, surface morphology, optical and electrical properties of as-deposited ZnO thin films at different growth temperatures were studied. Substrate temperature was varied from 100 to 600 °C at constant oxygen percentage O₂/(O₂ + Ar) % of 66.67 % in a mixed gas of Ar and O₂ with constant chamber pressure of 2.75 × 10^?4 mBar. X-Ray diffraction analyses revealed that all the films had (002) preferred orientation. The minimum value of stress was reported to be ?0.32 × 10¹⁰ dyne/cm² from ZnO film grown at 200 °C. Photoluminescence measurements demonstrated sharp near-band-edge emission (NBE) was observed at ~375 nm along with deep level emission (DLE) in the visible spectral range at room temperature. The DLE Peak was found to have decrement as ZnO growth temperature was increased from 200 to 600 °C. The minimum FWHM of the NBE peak of 16.76 nm was achieved at 600 °C growth temperature. X-Ray photoelectron spectroscopy study revealed presence of oxygen interstitials and vacancies point defects in ZnO film grown at 400 °C. The ZnO thin film was found to be highly resistive when grown at 100 °C. The ZnO films were found to be n-type conducting with decreasing resistivity on increasing substrate temperature from 200 to 500 °C and again increased for film grown at 600 °C. Based on these studies a correlation between native point defects, optical and electrical properties has been established.