聚乙炔离子注入掺杂及电性能的研究

本文用Ar~+,Fe~+,Cl~+,I~+,Na~+和K~+等离子束,在15—30keV能量范围内注入聚乙炔薄膜,剂量为1×10~(13)-3×10~(17)cm~(-2).借助红外光谱、卢瑟福背散射分析及四探针等测试方法,考察了离子注入诱导聚乙炔膜的化学结构及导电性能的变化,检测了化学掺杂与离子注入杂质的深度分布和p-n结的形成,并在此基础上探讨了离子束与聚合物相互作用过程的机理.     

镨和铕离子注入硅的快速热退火研究

利用离子注入技术将稀土Ｐｒ和Ｅｕ离子引入外延硅片中，经快速热退火使注入层再结晶和电激活。对Ｐｒ离子注入样品，在较低温度９４０℃下退火，样品具有电子导电性，注入离子起施主作用，而在较高强度１２４０℃下退火，则具有穴穴导电性，注入离子起受主作用，即有两种导电行为。     

聚苯胺薄膜的离子束效应

本文采用离子注入掺杂技术，研究了全氧化态聚苯胺薄膜的离子束效应．‘４０ｋＶＫ＋离子束注入后，聚苯胺薄膜的电导率随着剂量的增加而迅速增加．当剂量为１×１０１７Ｋ＋／ｃｍ２时，电导率增加了８个数量级．ＦＴＩＲ光谱图显示了Ｋ＋离子注入使全氧化态聚苯胺中的醌亚胺结构发生还原反应．温差电流法测量表明，离子注入区呈现ｎ型半导体特性．四探针法测量了离子注入掺杂聚苯胺的电导率与温度的关系．本文还对离子注入掺杂全氧化态聚苯胺的导电机制进行了初步探讨．     

离子掺杂氧化锌光催化纳米功能材料的制备及其应用

氧化锌是一种氧化还原电位高、激子结合能大（~60 meV）、物理和化学稳定性较好、廉价且无毒的半导体光催化剂。本文综述了掺杂氧化锌光催化剂的掺杂离子类型、制备方法、光催化效果及其作用机理。掺杂氧化锌的离子类型主要包括非金属离子单掺杂、金属离子（包括过渡金属离子和稀土金属离子）单掺杂和双离子共掺杂。离子掺杂后可在氧化锌晶格中引入更多的氧空穴或缺陷,为光致氧化反应提供更多的活性位点;或者引入杂质能级,扩大光吸收范围,增强可见光吸收能力。同时,掺杂的离子也可作为电子捕获中心,阻止光生电子-空穴对的复合,从而提高氧化锌光催化剂的性能。此外,文中还对掺杂氧化锌光催化剂在有机污染物降解、抗菌和光催化制氢等方面的应用进行了系统概述,并对其发展趋势作了展望。     

单晶硅氩离子注入层的微观结构和微观摩擦磨损行为

利用离子注入技术对单晶硅表面进行了氩离子注入,用微摩擦磨损实验机研究了改性层的摩擦磨损行为,并用透射电子显微镜研究了改性层的微观结构.结果表明:经过一定剂量的氩离子注入后单晶硅的耐磨性能较注入前有了一定的提高,其中以注入剂量1×1016ions/cm2为最好,氩离子的注入使单晶硅表面形成了硅的微晶态与非晶态共存的混和态结构的改性层,使其具有良好的抗塑变和塑性剪切能力,从而改善了单晶硅的抗磨能力.     

钛、玻璃碳基体中离子注人镍的电化学性能

钛、玻璃碳基体中离子注入5×10~(16)×10~(1(?)Ni~+离子cm~(-2).在30%KOH溶液中测试这些电极对氢析出反应的电催化性能.结果表明,离子注入电极的催化活性优于未注入的钛、玻璃碳基体.由极化测量求得动力学参数j、b和E.这些数据表明,在离子注入电极上,氢析出反应的速度决定步骤与镍电极相似,由电化学放电步骤控制。AES测量表明,镍在钛基体中的深度分布近似高斯分布,在阴极极化过程中,注入的镍没有损失,但明显地移向深处.用XPS研究注入前后Ni_(2p)和Ti_(2(?))电子结合能所产生的位移表明,离子注入可能在基体表面形成合金.     

注入Y离子对Ni3Al合金高温氧化行为的影响

以40 KeV的能量和3×1017 /cm2的剂量在Ni3Al合金中注入Y离子, 利用热重分析、 X射线衍射、扫描电镜、能谱分析和划痕分析等技术研究了离子注入对其900 ℃恒温氧化行为的影响. 结果表明 注入Y离子不仅改变了合金的氧化动力学, 而且改变了其氧化机理. 注入Y离子后合金氧化产物中的NiO含量大为增加, 从而降低了合金的抗氧化性能. 但Y离子的注入使NiO晶粒细化, 增强了氧化膜的塑性和粘附性.     

低能氮离子与水的化学合成作用

化学改性是离子与物质相互作用的一种重要效应，即外来离子的介入引起材料中元素或基团间化学反应，更突出的是离子直接参与化合形成新的物质，从而改变材料的性质＊’1．近年来离子注入生物体产生独特的诱变效应引起了广泛关注问．注入离子在生物材料中引起的化学合成较好地解     

氮离子注入表面改性PBO薄膜及其性能

利用70keV能量的氮离子对聚苯并二噁唑(PBO)薄膜进行常温下离子注入表面改性,注入剂量(每平方厘米注入的氮离子数)从1×10~(15)N~+/cm~2到5×10~(16)N~+/cm~2。采用红外(FTIR)、拉曼(Raman)、光电子能谱(XPS)及原子力显微镜(AFM)对其表面结构、组成及形貌进行了表征。研究了氮离子注入剂量对PBO薄膜表面结构与性能的影响。结果表明:注入氮离子后,薄膜表面发生化学键的断裂和交联,近表面区域发生碳化。随氮离子注入剂量的增加,表面粗糙度增加,表面接触角从93°降低到60°,表面润湿性提高了35%,电导率提高到5.7×10~(-9)S/cm,比纯PBO薄膜增加了3个数量级。     

铁基体离子注入钯的腐蚀行为

研究了铁基体离子注入钯后的腐蚀行为。钯离子注入剂量为１×１０＾６～１×１０＾１８离子．ｃｍ＾－２注入能量４０ｄｅＶ．在ｐＨ＝５．０的０．５ｍｏｌ／Ｌ ＮａＡｃ／ＨＡｃ缓冲溶液中，用动电位扫描法测量了注钯后的铁的阳极溶解过程，用开腐蚀电位与浸泡时间的关系研究了修饰材料的耐蚀性。结果表明，钯离子的注入降低了铁的临界钝化电流，在ｐＨ＝５．０的醋酸盐缓冲溶液中保持较好的钝性。但当注入电极表面的氧化膜被还原     

Ion implantation doping and electrical properties of high-temperature ladder polymers

We report the first ion implantation doping studies on high-temperature ladder polymers and show that insulting films of the benzimidazobenzophenanthroline-type ladder polymer (BBL) can be doped by boron, argon, and krypton implantation to conductivities as high as 224 S/cm at a dose of 4.0 × 10¹⁶/cm² while retaining the excellent mechanical properties of the pristine films. Effects of dose (ions/cm²) and beam current density (microamps/cm²) on electrical conductivity at fixed ion energies are reported. The temperature dependence of the conductivity indicates that the implanted ladder polymer films are semiconductors. Spatially selective implantation, creating regions of conducting lines in an insulating matrix, which suggests microelectronic device applications of the ladder polymers, is demonstrated.     

Electrical properties of ion-implanted poly(p-phenylene sulfide)

Ion implantation of impurities into thin films of poly(p-phenylene sulfide) (PPS) is found to increase the conductivity of the material by up to 12 orders of magnitude. The increase is stable under exposure to ambient conditions, in contrast to the instability of the conductivity increases in PPS produced by chemical doping with AsF₅. PPS films 0.1–0.2 μm thick are spin cast from solution onto interdigitated electrodes patterned on an oxidized silicon substrate. The room-temperature interelectrode resistance is measured as a function of implantation fluence. An estimate of film conductivity is obtained from this resistance with a simple model for the electrode and film geometry. A first experiment yielded similar conductivity increases for implantation of either arsenic or krypton. At a fluence of 1 × 10¹⁶cm^?;2, which corresponds to an average impurity concentration of 2.5 × 10²¹cm^?3, the conductivity reaches an apparently saturated value of 1.5 × 10^?5 (Ω cm)^?1. Infrared spectra of the films before and after implantation suggest that crosslinking may be present in the implanted films, and Auger studies show stoichiometric changes throughout the implanted layer. These results suggest that the observed conductivity changes are the result of molecular rearrangements produced by the implantation rather than the result of specific chemical doping. Specific chemical doping may, however, explain the results of a second experiment in which implantation of bromine resulted in substantially larger conductivities found to increase at an approximate linear rate from a value of 1.0 × 10^?4 (Ω cm)^?1 at a fluence of 1 × 10¹⁶ cm^?2 to a value of 4.0 × 10^?4 (Ω cm)^?1 at a fluence of 3.16 × 10¹⁶ cm^?2.     

Effect of N5+ ion implantation on optical and gas sensing properties of WO3 films

In this paper we report the optical and gas sensing behaviours of tungsten oxide (WO₃) films, implanted with 45‐keV N^{5 +} ions of different fluences in the range 1 × 10¹⁵ to 1 × 10¹⁷ cm^–2. The film with fluence 1 × 10¹⁵ cm^–2 shows the most intense PL spectrum with two prominent peaks near UV and blue regions. The morphological changes because of ion implantation are also investigated by atomic force microscopy. Because of implantation the gas sensitivity of the film, in exposure of methane, is found to increase with reasonably fast response and recovery times. With the increase of the concentration of methane, the sensors show better result. Present work also includes the effect of N^{5 +} ion implantation on the structural property of WO₃ films. Copyright © 2015 John Wiley & Sons, Ltd.     

Focused ion beam implantation of Ga in Si and Ge: fluence‐dependent retention and surface morphology

Focused ion beam implantation of 30‐keV Ga⁺ ions in single‐crystalline Si and Ge was investigated by SIMS, using Cs⁺ primary ions for sputtering. Nine different implantation fluences ranging from 1 × 10¹³ to 1 × 10¹⁷ Ga⁺‐ions/cm² were used, with implanted areas of 40 × 40 µm². The Ga concentration distributions of these implants were determined by SIMS depth profiling. Such 30‐keV Ga implantations were also simulated by a dynamic Monte‐Carlo code that takes into account the gradual change of the near‐surface composition due to the Ga incorporation. In both approaches, an essentially linear increase of the Ga peak concentrations with fluence is found up to ～1 × 10¹⁶cm^?2; for higher fluences, the Ga content approaches a saturation level which is reached at about (1–2) × 10¹⁷cm^?2. The measured and simulated peak concentrations of the Ga distributions are in good agreement. The most probable ranges obtained from the experiments correspond closely with the respective values from the simulations. The surface morphology caused by Ga⁺ implantation was investigated by atomic force microscopy (AFM). The AFM data indicate that for low fluences (<3 × 10¹⁵cm^?2) the surface within the implanted areas is growing outward (i.e. is swelling). For increasingly higher fluences, sputter‐induced erosion of the surface becomes dominant and distinct craters are formed for fluences above ～1 × 10¹⁶cm^?2. At the boundary of the implanted region a wall‐like structure is found to form upon Ga implantation; its height is growing with increasing fluence, reaching a value of ～15 nm at 1 × 10¹⁷ Ga⁺‐ions/cm². Copyright © 2008 John Wiley & Sons, Ltd.     

低碳钢基体中离子注入镍和钼的电催化活性

离子注入不受相律和化学平衡的限制,也不受离子源和基体种类的约束,注入离子的能量和剂量精确可控,因而它是实现材料表面改性最有效的方法之一.自Grenness等发现注铂的钨电极,对H~+还原的电催化性能与纯铂接近之后,Wolf等将注入的Pt/RuO_2、Pt/C、Pt/WC电极用于H~+、O_2的电化学还原及甲酸的电化学氧化,其催化活性和稳定性均优于光滑的纯铂电极、Thompson等在钛基上注铂,用于催化析氢也得到类似的效果。近期文献报导,用热处理或电沉积方法制备的Ni-Mo、Ni-Mo-V 合金电极有很低的析氢超     

High-energy ion implantation of polymers: Poly(ethylene terephthalate)

The effect of high-energy ion implantation of oxygen into a thin film of poly(ethylene terephthalate) (PET) was studied by Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC). Mylar samples 13 μm thick were implanted with 6-MeV oxygen ions at fluences ranging from 5 × 10¹² to 2 × 10¹⁴ ions/cm². The DSC data showed a substantial loss of crystallinity, even at the lowest fluence, which extended deeper into the polymer film than the predicted range for oxygen deceleration in PET. Solubility measurements indicated the presence of cross-linking, especially at the highest fluence, but bands due to cross-linking could not be detected in the infrared. The trans/gauche ratio for the glycol group conformation was measured by a pair of conformationally sensitive infrared bands. Surprisingly, the conformation of the glycol segments did not change appreciably with increasing fluence, although crystallinity decreased and degree of cross-linking increased. The implications these results have on possible mechanisms of chemical and physical alterations of the polymer structure by ion implantation are discussed.     

Study of thermal recrystallisation in Si implanted by 0.4-MeV heavy ions

A Si crystal layer on SiO₂/Si was implanted using 0.4-MeV Kr⁺, Ag⁺, and Au⁺ at ion fluences of 0.5 × 10¹⁵ to 5.0 × 10¹⁵ cm⁻². Subsequent annealing was performed at temperatures of 450° and 800° for 1 hour. The structural modification in a Si crystal influences ion beam channelling phenomena; therefore, implanted and annealed samples were investigated by Rutherford backscattering spectrometry under channelling (RBS-C) conditions using an incident beam of 2-MeV He⁺ from a 3-MV Tandetron in random or in aligned directions. The depth profiles of the implanted atoms and the dislocated Si atom depth profiles in the Si layer were extracted directly from the RBS measurement. The damage accumulation and changes in the crystallographic structure before and after annealing were studied by X-ray diffraction (XRD) analysis. Lattice parameters in modified silicon layers determined by XRD were discussed in connection to RBS-C findings showing the crystalline structure modification depending on ion implantation and annealing parameters.     

Conductive and optical properties of PPV modified by N+ ion implantation

In this article, a soluble poly[2‐methoxy‐5‐(3′‐methyl)butoxy]‐p‐phenylene vinylene (MMB‐PPV) was synthesized by dehydrochlorination reaction and the MMB‐PPV film was implanted by nitrogen ions (N⁺) with the ion dose and energy in the range of 3.8 × 10¹⁵ to 9.6 × 10¹⁶ ions/cm² and 15–35 keV, respectively. The surface conductivity, optical absorption, optical band gap (E_g) of modified MMB‐PPV film were studied, and the third‐order nonlinear optical susceptibility (χ⁽³⁾) as well as its environmental stability of modified MMB‐PPV film were also measured by degenerate four‐wave mixing system. The results showed that the surface conductivity of MMB‐PPV film was up to 3.2 × 10^?2 S when ion implantation was performed with the energy of 35 keV at an ion dose of 9.6 × 10¹⁶ ions/cm², which was seven order of magnitude higher than that of the pristine film. UV‐Vis absorption spectra demonstrated that the optical absorption of MMB‐PPV film was enhanced gradually in the visible region followed by a red shift of optical absorption threshold and the E_g value was reduced from 2.12 eV to 1.59 eV with the increase of ion dose and energy. The maximum χ⁽³⁾ value of 2.45 × 10^?8 esu for modified MMB‐PPV film was obtained with the ion energy of 20 keV at an ion dose of 3.8 × 10¹⁶ ions/cm², which was almost 33 times larger than that for pristine film. In comparison to the reduction of 17% in the χ⁽³⁾ value of pristine MMB‐PPV film, the maximum χ⁽³⁾ value of 2.45 × 10^?8 esu for modified MMB‐PPV film decreased by over 5.3% when they had been exposed under the same ambient conditions for 90 days. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2072–2077, 2010     

低能离子与生物有机小分子相互作用机制的初步研究

利用低能离子束(N^+,Ar^+离子)辐照固态羧酸钠(甲酸钠)、(乙酸钠)、(苯甲酸钠)和固态嘧啶碱基两类样品,经电子顺磁共振谱(EPR)、富里叶红外光谱(FT-IR)的检测,结果发现,三种低能离子辐照后的甲酸钠样品中产生了[COO]^.^-自由基和亚甲基(CH2),氮离子辐照乙酸钠和苯甲酸钠样品后,形成了新的化学基团氰基(CN);同时,结合茚三酮反应,证明了辐照后的羧酸钠和碱基样品中还含有新的基团氨基(NH2),给出了氨基的产生量与注入离子的剂量的相关曲线。