Properties of Indium-Doped ZnO Films Prepared in an Oxygen-Rich Plasma

Indium-doped zinc oxide (ZnO:In) films were prepared in an Ar:O₂ plasma by reactive magnetron sputtering. The x-ray diffraction (XRD) patterns presented the crystal structures of ZnO:In films, while transmission spectra and photoluminescence (PL) spectra showed the changed band gap and the visible emission from defects, as compared to the PL spectra of undoped ZnO films. It was concluded that the increase of substrate temperature enhanced the crystal quality of ZnO:In films; the incorporation of In made the c-axis constant of the samples larger than that of undoped ZnO films; the blue emission was due to the transition from an unknown donor level by indium doping to the valance band; and the orange-green emission originated from acceptor defects (O_Zn) formed in the O-rich plasma. Meanwhile, the current- voltage characteristics and persistent photoconductivity phenomenon also could be explained by the increased acceptor defects (O_Zn) that formed when the substrate temperature was increased.     

离子注入对ITO薄膜电学特性的影响

对系列In2O3∶Sn (ITO)薄膜样品分别实施了不同剂量的Sn+, Ag+ 和Mo+离子注入并将它们在250 ℃下进行了热处理.利用霍耳测量研究了原始样品及注入和退火前后各样品的电学特性.研究了ITO薄膜的电学参数受离子注入的种类及剂量的影响.实验证明不同种类的离子注入会不同程度地降低ITO的导电性能,但热处理的效应与之相反.3种金属中,Sn+离子对薄膜造成的注入损伤最小,而高价的钼离子可以替换铟离子的位置成为施主,当注入剂量为1×1015 cm-2时,经过Mo+离子注入和后续退火的ITO薄膜,载流子浓度提高了14%.     

He Ion Implantation and the Refractive Index Depth Profile in Relaxor Ferroelectric Optical Waveguides

This work reports the impact of He ion implantation conditions on the depth-dependent refractive index profile n(z) defining optical waveguides in 95.5% Pb(Zn_1/3Nb_2/3)O₃-4.5%PbTiO₃ (4.5% PZN-PT). Two hypotheses are investigated. The first is that n(z) follows the same functional form as the energy deposited into the lattice for all implantation conditions. The second is that the effective refractive indices for fully confined propagating modes can be accurately predicted by a simple step-function analytical approximation. Experimentally observed prism-coupled reflectivity data are collected from 4.5% PZN-PT samples implanted with 1.0 MeV He ions for doses varying from 7.5 × 10¹⁴ ions/cm² to 1 × 10¹⁷ ions/cm² and with 3.8 MeV He ions for doses varying from 1 × 10¹⁵ ions/cm² to 5 × 10¹⁶ ions/cm². For doses less than 5 × 10¹⁶ ions/cm², the data are consistent with a functional form of n(z) following that of the energy deposited to the lattice. The confined modes are accurately described by a step-function approximation to n(z). These data and analyses result in the ability to design waveguides in PZN-PT through choosing implantation conditions that deposit the appropriate energy profile. This is not the case for the highest implantation doses, potentially signaling a difference in the type of structural modification that occurs.     

有序结构ZnO的自组装生长及光学性能研究

利用重力场下的自组装,将单分散的ZnO胶体球悬浮液自组装为排列有序的结构。通过SEM、TEM对制得的有序结构进行了表征。结果表明,这种方法可得到直径为50~800 nm的ZnO胶体球。所得样品的透射谱在200~1 100 nm范围内出现一强烈的衰减峰(带隙中心波长为λc),且λc随ZnO胶体球粒径的减小向短波长方向移动(蓝移),λc的位置还随前处理温度的降低而蓝移。     

S掺杂纤锌矿ZnO的光催化性质的第一性原理研究

利用基于密度泛函理论的第一性原理,研究了硫(S)掺杂纤锌矿氧化锌(ZnO)的能带结构、态密度和光学性质。结果表明:掺杂后晶格畸变,晶格常数随着掺杂量的增加而增大;S原子掺杂减小了能带间隙,提高了电子跃迁的概率;进一步的光学性质计算发现,S掺杂后吸收谱出现红移,且吸收谱峰值随掺杂量的增加而增大,提高了可见光和紫外光区域的光吸收。     

雾化热解法制备ZnO薄膜及其光电性能

采用超声雾化技术,以醋酸锌水溶液为源物质,在加热的玻璃衬底上生长了ZnO薄膜,并研究了衬底温度等因素对薄膜结构及其光、电性能的影响.结果表明其为六方晶体(纤锌矿)结构,在适当的条件下,可以生长出具有较强c轴取向的ZnO薄膜,所得到的ZnO薄膜具有低达7.68×1010cm-3的载流子浓度,这对实现ZnO的p型掺杂具有重要意义.     

溅射法制备ZnO薄膜结构及光学特性

采用直流磁控溅射镀膜工艺在玻璃基片上沉积了具有良好c轴择优取向的znO薄膜.用组合式多功能光栅光谱仪测得透光率均在85%以上;用AXRF分析了退火前后薄膜的物相,并用原子力显微镜分析了薄膜的表面形貌.样品通过空气中退火,薄膜结晶质量明显提高,晶粒有所长大,取向更加一致.在室温下用荧光分光光度计分析了薄膜的发光特性,观测到明显的紫外光发射(波长为386 nm)和波峰为528nm的一"绿带"宽峰.紫外发射是由于导带和价带之间的电子跃迁,宽峰是源于晶体的缺陷.     

Magnetic Properties of Fe-Implanted ZnO Nanotips Grown by Metal-Organic Chemical Vapor Deposition

Fe ions were implanted into well-aligned single-crystal ZnO nanotips grown on SiO₂/quartz substrates using metal-organic chemical vapor deposition (MOCVD). The Fe ion concentration distribution within a single nanotip is mapped by electron energy loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) and the nanotips imaged by high-resolution transmission electron microscopy (TEM). X-ray absorption spectroscopy (XAS) identified the presence of Fe²⁺ and Fe³⁺ ions in both as-implanted and annealed samples. However, Fe³⁺ ion concentration increased during postannealing. Superconducting quantum interference device (SQUID) measurements show that the as-implanted and postannealed ZnO nanotips are ferromagnetic at room temperature. The observed ferromagnetism in the as-implanted nanotips is primarily attributed to the near surface 10-nm region that has high Fe concentration. The saturation magnetization reduces after annealing.     

Be掺杂对ZnO电子结构和光学性质的影响

基于密度泛函理论(DFT)第一性原理计算了Zn1-xBexO化合物的电子结构和光学性质.计算结果表明Zn1-xBexO带隙随掺杂浓度的增加而变大.这种现象主要是由于价带顶O2p随掺杂量x的增加几乎保持不变,而Zn4s随掺杂最x的增加向高能端移动.光学介电函数虚部计算结果表明:在2.0,6.76eV位置随掺杂浓度的增加蜂形逐渐消失,是由于Be替代Zn导致Zn3d电子态逐渐减少所致;而9.9eV峰彤逐渐增强,是由于逐渐形成的纤锌矿结构Beo的价带O2p到导带Be2s的跃迁增加所致.     

Be掺杂对ZnO电子结构和光学性质的影响

基于密度泛函理论（DFT）第一性原理计算了Zn1-xBexO化合物的电子结构和光学性质. 计算结果表明Zn1-xBexO带隙随掺杂浓度的增加而变大. 这种现象主要是由于价带顶O2p随掺杂量x的增加几乎保持不变,而Zn4s随掺杂量x的增加向高能端移动. 光学介电函数虚部计算结果表明：在2.0, 6.76eV位置随掺杂浓度的增加峰形逐渐消失,是由于Be替代Zn导致Zn3d电子态逐渐减少所致;而9.9eV峰形逐渐增强,是由于逐渐形成的纤锌矿结构BeO的价带O2p到导带Be2s的跃迁增加所致.     

Al掺杂对ZnO薄膜形貌和光学性能的影响

采用溶胶-凝胶旋涂法在FTO玻璃衬底上制备得到了不同Al掺杂浓度的ZnO薄膜(AZO)。利用XRD、FESEM、UV-vis和PL等测试手段对样品结构、形貌和光学性能进行了表征。结果表明,合成的AZO薄膜均为六方纤锌矿结构且峰强随掺杂浓度的升高而减弱;同时,颗粒形貌由不规则向规则球形转变且尺寸逐渐减小;PL谱中的近紫外发射峰和晶格缺陷峰值随掺杂浓度的升高先增大后降低;由UV-vis吸收光谱可知,AZO薄膜在设定波长内的光吸收处于波动状态,且当Al掺杂浓度为3%时,光吸收强度最高,禁带宽度减小到3.12eV。     

由浅离子注入实现的MQW混合

用浅Ｐ＾＋离子注入ＩｎＧａＡｓ／ＩｎＧａＡｓＰ应变多量子阱（ＭＱＷ）激光器Ｈ２／Ｎ２混合气氛下的快速退火,体内ＭＱＷ层发生组份混合（ｉｎｔｅｒｍｉｘｉｎｇ）,导致器件的带隙波长蓝移（ｂｌｕｅ ｓｈｉｆｔ）,结构的光荧光（ＰＬ）峰值波长向短波方向移动了７６ｎｍ。作者认为,有源区中的应力对量子阱混合起到了十分关键性的作用。     

衬底温度对磁控溅射法制备的ZnO:In薄膜光电性能的影响

以粉末靶为溅射源,采用射频磁控溅射法在玻璃衬底上制备掺铟氧化锌(ZnO:In)透明导电膜.利用X射线衍射仪、原子力显微镜、霍尔测试仪,以及分光光度计等对不同衬底温度下生长的ZnO:In薄膜的结构、光电性能进行表征.结果表明,所有制备的ZnO:In薄膜均为六角纤锌矿结构的多晶膜,具有(002)择优取向.ZnO:In薄膜的电阻率随着衬底温度的升高先减小后增大,当衬底温度为100℃时,薄膜的最低电阻率为3.18×10~(-3)Ω·cm.制备的薄膜可见光范围内透过率均在85%以上.

Abstract：

Indium doped zinc oxide (ZnO : In) films were deposited on glass substrates by RF magnetron sputtering method using a powder target.The influence of the substrate temperature on the structure,optical and electrical properties was investigated by X-ray diffraction (XRD),atom force microscope (AFM),Hall measurement and optical transmission spectroscopy.The results show all the obtained films are polycrystalline with a hexagonal wurtzite structure and grow preferentially in the (002) direction,and the grain size is about 22～29 nm.The conductivity of the ZnO : In films change with the substrate temperature,and the lowest electrical resistivity is about 3.18 × 10~3 Ω·cm for the samples deposited at substrate temperature 100 ℃.The transmittance of our films in the visible range is all higher than 85%.     

锰掺杂ZnO稀磁半导体的制备及铁磁性能

用溶胶-凝胶法,在超声波辅助条件下制备了Mn掺杂ZnO(Zn1-xMnxO,x≤0.05)稀磁半导体(DMS)纳米晶粉末样品.用透射电子显微镜(TEM)、X射线衍射(XRD)仪、超导量子干涉(SQUID)测磁仪分别对样品形貌、结构和磁性能进行了表征.较低的掺杂浓度下样品很好地保持ZnO的纤锌矿结构,随着掺杂浓度x的增加,样品的晶格常数近似线性增大,没有观察到杂质相.样品Zn0.98Mn0.02O显示了很好的铁磁性,居里温度在350 K以上.     

溶胶-凝胶法制备Al3+掺杂ZnO薄膜的结构和光学性能

采用无机盐溶胶-凝胶方法在载玻片衬底上制备了ZnO:Al薄膜,利用X射线衍射(XRD)、紫外-可见光透射光谱(UV-Vis transmittance spectrum)和扫描电镜(SEM)研究了退火温度和Al3+掺杂浓度对ZnO:Al薄膜结构和光学性能的影响.结果表明,随退火温度的升高或进行适当浓度的Al3+掺杂,可...     

Magnetic effects of direct ion implantation of Mn and Fe into p-GaN

In p-GaN implanted with Mn (3×10¹⁶ cm⁻² at 250 keV), the material after annealing shows ferromagnetic properties below 250 K. Cross-sectional transmission electron microscopy (TEM) revealed the presence of platelet structures with hexagonal symmetry. These regions are most likely Ga_xMn_1−xN, which produce the ferromagnetic contribution to the magnetization. In p-GaN implanted with Fe, the material after annealing showed ferromagnetic properties at temperatures that were dependent on the Fe dose, but were below 200 K in all cases. In these samples, TEM and diffraction analysis did not reveal any secondary phase formation. The results for the Fe implantation are similar to those reported for Fe doping during epitaxial growth of GaN.     

掺Al对ZnO薄膜结构和光电性能的影响

采用溶胶-凝胶工艺在普通玻璃片上制备了ZnO∶Al薄膜。通过XRD、UV透射谱和电学测试等分析方法研究了掺Al对薄膜的组织结构和光电性能的影响。分析表明:所制备的薄膜具有c轴择优取向,随着掺Al浓度的增加,(002)峰向低角度移动,峰强逐渐减弱。薄膜电阻率随掺Al浓度变化,当掺Al浓度为1.5%(摩尔分数),薄膜电阻率降至6.2×10-4Ω·cm。掺Al量的增加同时使得薄膜的禁带宽度变大,光吸收边出现蓝移现象。     

黑硅无掩模反应离子刻蚀法制备及光学性能研究

采用无掩模反应离子刻蚀法制备了黑硅.利用扫描电子显微镜及紫外-可见-近红外分光光度计研究了黑硅的微结构和光学特性.结果表明,黑硅微结构高度为2.0～3.5 μm,径向尺寸90～400 nm,间距200～610 nm.在400～1 000 nm光谱范围内黑硅吸收率为94％,是单晶硅的1.5倍;在1 200～1 700 nm光谱范围吸收率为55％～60％,是B掺杂单晶硅的20倍.制备的黑硅的光学带隙为0.600 6 eV,吸收光谱明显向红外方向偏移.     

离子注入对二氧化锡薄膜的改性作用

对溅射沉积制成的氧化锡薄膜进行了钨离子注入、氧离子注入和退火处理，并用X射线衍射(XRD)和x射线光电子能谱(XPS)分析了薄膜，研究了注入对薄膜相变的影响。发现在室温下溅射沉积形成的非晶态SnO2薄膜，注入氧离子后导致了非晶态SnO2向晶态SnO2的转变；注入钨离子则导致了SnO在非晶态薄膜中的形成。而在已经注入了钨离子的薄膜中再注入氧离子可以形成Sn3O4。实验表明，注入钨离子可减少由氧和锡组成相的氧、锡比率，而注入氧离子则可增加这种比率。     

基于第一性原理的Ga-Eu共掺ZnO光电性质的研究

采用基于密度泛函理论的第一性原理方法,分析了Ga-Eu共掺杂ZnO(GEZO)结构的能带结构、态密度、马利肯布居分布以及光学性质。结果表明,计算得到的晶格常数及带隙与实验值一致。Ga,Eu的掺入贡献了导电载流子,使体系的电导率增强。费米能级进入导带,呈现n型导电。从态密度中可知费米能级处出现了由Eu的4f态引入的杂质带,Ga也在导带底处贡献了4p和4s态。原子和键的平均马利肯布居分布表明,Ga,Eu原子的掺入增强了键的离子性。光学性质方面,Ga,Eu的掺入使得介电函数实部和虚部的峰位向低能区转移,吸收率和反射率在可见光区均有提高。