注入Nb+的蓝宝石晶体退火前后的光学分析

将Nb⁺ 在不同条件下注入不同晶向的蓝宝石晶体，然后，在还原性气氛下退火，并对退火前后的蓝宝石晶体进行光学分析。分析结果表明，Nb⁺ 注入蓝宝石晶体产生的色心缺陷主要集中在紫外和可见光的高能区。通过对光吸收谱进行高斯拟合及荧光谱分析确认，引起吸收的点缺陷主要是F、F⁺、F₂、F⁺₂、F²⁺₂心等阴离子空位。退火可使这些色心点缺陷减少。退火温度越高，色心点缺陷减少越多，且减少的程度与注入温度有关。此外，700nm处的荧光峰随激发光波长变化而呈现出不同的变化趋势。     

C注入GaN光致发光和微区拉曼散射的研究

使用光致发光谱和微区拉曼散射谱的测量,研究了C离子注入原生无黄光发射的GaN。C离子的注入剂量范围为1013-1017cm-2。发光谱的研究表明,C注入的GaN经950℃高温退火后出现了黄光发射,而近带边发射峰的峰位则由于C注入产生的某种缺陷而发生了蓝移。拉曼谱的测量表明,GaN薄膜的应力不随C注入而改变。当注入剂量增加至1015cm-2时,出现了与无序激活拉曼散射相关的300cm-1峰,但随着注入剂量进一步增加,300cm-1峰减弱并未消失,这被归因于注入束流强度随注入剂量增大。     

O、C离子注入n型GaN的黄光发射研究

采用光致发光(Photoluminescencc,PL)谱的测量,研究了1012～1017cm-2的O和C两种离子注入和退火对非有意掺杂的n型GaN黄光发射(Yellow luminescence,YL)的影响,注入后的样品在流动N2的保护下进行退火,退火温度950℃,退火时间30 min.对比相同剂量下N离子注入GaN黄光发射,结果表明O、C两种离子的注入在GaN中分别引入了与黄光发射相关的不同的深能级中心,当C离子注入剂量高达1017cm-2时,能引起黄光发射的C相关的深能级中心显著增多.     

MeV碳离子及碳团簇C2+注入PC膜的光吸收谱研究

研究了MeV碳离子及碳团簇C2 注入的聚碳酸酯(Polycarbonate,PC)膜.光吸收谱研究结果表明,离子注入在聚合物近表面产生了断键及缺陷,改变了PC的光吸收性质,在可见光区域有较明显的吸收,并且吸收边与注入离子的种类、能量和注量密切相关.X射线光电子谱(X-ray photoelectron spectroscopy,XPS)对PC的近表面结构和成分配比进行了分析,证实了以上的结论.     

同轴型HpGe探测器离子注入工艺仿真

为了进一步优化同轴型高纯锗探测器离子注入工艺参数,利用Silvaco半导体仿真软件和SRIM离子注入仿真软件对离子注入过程进行模拟,研究不同注入角度、能量、剂量对注入的均匀性、深度、杂质浓度分布及损伤的影响,并根据模拟结果选择合适的工艺参数,为HpGe探测器的制备提供一定的指导。此外,研究了离子注入后退火的温度及时间对晶格损伤恢复和杂质激活的影响情况。     

~(57)Fe注入铜的穆斯堡尔效应研究(Ⅱ)——注入特性和铁磁相变化

我们曾报道了在同一剂量下的~(57)Fe离子注入铜随退火温度变化的特性,观察到注入铁离子所处的三种不同位:固溶态的孤立铁原子、具有二个或更多铁原子结合在一起的固溶态原子组团(Cluster)和γ-Fe夹杂相;经一定温度退火后,固溶态的铁原子和γ-Ee分别通过凝聚和相变转变成具有体心立方结构的α-Fe;在600℃退火后α-Fe全部消失转变成固溶态铁。本文着重报道不同的~(57)Fe注入剂量对铁原子不同位的强度和它们的超精细参数的影响以及它们随不同退火温度的变化关系。     

大剂量P^＋离子注入单晶硅的研究

采用４８０ｋｅＶ Ｐ＾＋离子注入单晶硅，注入剂量为１×１０＾１６ｃｍ＾－２。采用ＲＢＳ、ＴＥＭ技术测试样品，发现样品经６００℃退火后，距样品表面约２４０ｎｍ处有一条低密度缺陷带。研究表明，这一现象与Ｐ＾＋的剂量及退火温度有关。     

离子注入C60薄膜的电导率变化

沉积在云母片上的纯Ｃ６０薄膜受２０ｋｅＶ的Ｌｉ＋和Ｎ＋２离子轰击，剂量在０．５×１０１６／ｃｍ２～５．０×１０１６／ｃｍ２之间改变，测量了离子注入后Ｃ６０薄膜方块电阻随温度的变化，进而推导出Ｃ６０薄膜电导率随温度和注入离子剂量的变化；分析了非原位测量中氧元素对电导率变化的影响以及能量较高的注入离子对Ｃ６０薄膜的辐照损伤效应。研究结果表明，Ｌｉ＋注入对Ｃ６０薄膜电导率的影响明显高于Ｎ＋２注入的影响，并给出了不同离子注入条件下Ｃ６０薄膜电导率随温度变化的函数关系式。     

用正电子湮没实验研究PbWO4新型闪烁晶体绿光发光机理

通过正电子湮没寿命谱研究ＰｂＷＯ４晶体退火处理前后缺陷的变化,发现氧退火后,晶体正电子寿命值τ２变小,正电子捕获率ｋ增大,真空退火反之。并且ＰｂＷＯ４晶体氧退火后发光主峰位从４４０ｎｍ称到４８５ｎｍ的绿光处,而真空退火晶体发射谱谱形并未变化。从不同退火处理对晶体的影响,提出了ＰｂＷＯ４晶体中铅空位形成ＷＯ３＋Ｏ＾－发绿光的发光模型。     

离子注入的氙和铯在硅和铝中的表面富集现象

近几年来,人们研究了离子注入层中注入杂质在退火过程中的再分布。结果表明,广泛的离子品种,例如Pb~ 、As~ 、Sb~ 、Cs~ 、Pt~ 、Bi~ 、Xe~ 、Ni~ 、Br~ 和Cr~ 等高剂量(≥10~(15)atoms/cm~2)注入Si后,在退火时注入的杂质显著地向表面扩散;高剂量离子注入某些金属,退火时也有向表面扩散的现象。因此,高剂量注入的杂质在退火过程中向表面扩散是一个较普遍的现象。     

XPS and optical studies of Xe-implanted and annealed YSZ single crystals

Xe⁺ ion implantation with 200 keV was completed at room temperature up to a fluence of 1 × 10¹⁷ ion/cm² in yttria-stabilized zirconia (YSZ) single crystals. Optical absorption and X-ray photoelectron spectroscopy (XPS) were used to characterize the changes of optical properties and charge state in the as-implanted and annealed crystals. A broad absorption band centered at 522 or 497 nm was observed in the optical absorption spectra of samples implanted with fluences of 1 × 10¹⁶ ion/cm² and 1 × 10¹⁷ ion/cm², respectively. These two absorption bands both disappeared due to recombination of color centers after annealing at 250 °C. XPS measurements showed two Gaussian components of O_1s spectrum assigned to Zr–O and Y–O, respectively, in YSZ single crystals. After ion implantation, these two peaks merged into a single peak with the increasing etching depth. However, this single peak split into two Gaussian components again after annealing at 250 °C. The concentration of Xe decreased drastically after annealing at 900 °C. And the XPS measurement barely detected the Xe. There was no change in the photoluminescence of YSZ single crystals with a fluence of 1 × 10¹⁷ ion/cm² after annealing up to 900 °C.     

Color center annealing and ageing in electron and ion-irradiated yttria-stabilized zirconia

We have used X-band electron paramagnetic resonance (EPR) measurements at room-temperature (RT) to study the thermal annealing and RT ageing of color centers induced in yttria-stabilized zirconia (YSZ), i.e. ZrO₂:Y with 9.5 mol% Y₂O₃, by swift electron and ion-irradiations. YSZ single crystals with the 1 0 0 orientation were irradiated with 2.5 MeV electrons, and implanted with 100 MeV ¹³C ions. Electron and ion beams produce the same two color centers, namely an F⁺-type center (singly ionized oxygen vacancy) and the so-called T-center (Zr³⁺ in a trigonal oxygen local environment) which is also produced by X-ray irradiations. Isochronal annealing was performed in air up to 973 K. For both electron and ion irradiations, the defect densities are plotted versus temperature or time at various fluences. The influence of a thermal treatment at 1373 K of the YSZ single crystals under vacuum prior to the irradiations was also investigated. In these reduced samples, color centers are found to be more stable than in as-received samples. Two kinds of recovery processes are observed depending on fluence and heat treatment.     

Effect of annealing on the optical absorption of Ni nanoparticles in MgO single crystals

Ni⁺ ion implantation with an energy of 64 keV in MgO single crystals was conducted at room temperature up to a fluence of 1 × 10¹⁷ ion/cm². The as-implanted crystals were annealed isochronally at temperatures up to 900 °C. Optical absorption spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) have been utilized to characterize the changes of optical properties and the microstructure of the annealed samples. XPS results showed that the charge state of implanted Ni was still mainly in metallic Ni⁰ after annealing at 900 °C. TEM analysis revealed metallic Ni nanoparticles with depth-dependant dimensions of 1–10 nm in the annealed sample. Optical absorption spectroscopy indicated that the Ni nanoparticles exhibited a broad surface plasmon resonance absorption band in annealed samples and the band shifted to a longer wavelength with the increasing annealing temperature.     

Behaviors of optical and chemical state of Nb+ implanted sapphire after annealing

The behavior of the radiation damage of sapphire crystal ,produced by implantation with 380 keV Nb^ ion followed by annealing in a series of steps from 500to 11000℃ at reducing atmosphere,was investigated in optical absorption and XPS measurements.It is found that the implanted niobium in sapphire is in different local environments with different chemical states after the annealing,The changes in optical denstiy (OD) from the bands,based on the well known E-type centers,show that the annealing behavior of the radiation damage may be divided into different stages due to different mechansisms.     

The fabrication of planar waveguides on Bi12TiO20 crystals by oxygen and helium ion implantation

We report the first fabrication and characterization of optical planar waveguides in Bi₁₂TiO₂₀ crystals by ion implantation. For comparison we selected O²⁺ and He⁺ as our implanted ions. The loss value of the oxygen-implanted planar waveguide is reduced to 1.24 dB/cm after annealing at 260 °C for 30 min. The guided-mode profiles are successfully modeled through numerical simulations.     

Annealing behaviour of defects in helium implanted MgO

Virgin MgO (1 1 0) single crystals have been implanted with 30 keV ³He⁺ ions to a dose of 5 × 10¹⁵ cm^-2. After implantation the samples have been annealed under air for 30 min in a tube oven. The annealing behaviour of the defects and ³He has been monitored by three experimental techniques: positron beam Doppler broadening, neutron depth profiling (NDP) and optical absorption in the UV to near-IR region. The observations in MgO lead to the conclusion that below 1000^oC the vacancy like defects are stabilised by the implanted He atoms. Above this temperature He may dissociate from these small defects, allowing the formation of larger vacancy clusters.     

Comparison of the damage in sapphire due to implantation of boron, nitrogen, and iron

The damage microstructure and optical properties of sapphire implanted with boron, nitrogen and iron were examined by RBS-C, TEM, and optical absorption. Implantations were conducted at RT and 1000 °C at 150 keV and fluences of 3 × 10¹⁶-1 × 10¹⁷ ions/cm². Optical absorption measurements indicate that the boron-implanted samples contained the highest number of F-type centers and the nitrogen-implanted samples the fewest. The microstructure of the boron-implanted samples shows only ‘black-spot’ defect clusters, as did the iron-implanted samples at the lower fluences. At higher fluences, the iron implanted samples revealed the presence of nanometer-sized precipitates of single crystal bcc iron that contributed to additional optical scattering. Bubbles formed in samples implanted with low fluences of nitrogen. A second damage region is apparent in the RBS-C patterns for higher fluences of nitrogen.     

Effects of Ag and Au ion implantation of lithium niobate

The optical effects of implantation of lithium niobate crystals with 100 keV Ag⁺ and 8 MeV Au³⁺ ions with fluences of 1 × 10¹⁷ ions/cm² have been investigated. Metal nanoparticle formation has been studied as a function of annealing temperature, and the resulting optical extinction curves have been simulated by the Mie theory in the small particle limit. Transmission electron microscopy (TEM) has provided direct evidence for the MNP sizes allowing comparison with the calculated results. A TEM study of an X-cut sample implanted with Ag⁺ ions show that the implanted region is partially amorphised. The differences in the temperature of Au colloid development in X- and Y-cut faces of the lithium niobate crystal are attributed to restoration of crystallinity as a result of annealing.