Influence of deposition pressure on properties of ZnO: Al films fabricated by RF magnetron sputtering

Transparent conductive aluminum doped zinc oxide(ZnO:Al,AZO) films were prepared on glass substrates by rf(radio frequency) magnetron sputtering from ZnO: 3wt% Al_2O_3 ceramic target. The effect of argon gas pressure(PAr) was investigated with small variations to understand the influence on the electrical, optical and structural properties of the films. Structural examinations using X-ray diffraction(XRD) and scanning electron microscopy(SEM) showed that the ZnO:Al thin films were(002) oriented. The resistivity values were measured by four-point probe with the lowest resistivity of 5.76×10~(-4) Ω?cm(sheet resistance=9.6 Ω/sq. for a thickness=600 nm) obtained at the PAr of 0.3 Pa. The transmittance was achieved from ultravioletvisible(UV-VIS) spectrophotometer, 84% higher than that in the visible region for all AZO thin films. The properties of deposited thin films showed a significant dependence on the PAr.     

铝掺杂氧化锌薄膜的电学及光学性能

利用脉冲激光沉积法,在氧气氛下(氧分压为11 Pa)以石英玻璃为基体沉积了铝掺杂氧化锌薄膜。靶材选用锌铝合金靶,沉积过程中基体温度保持在150℃。研究了ZnO薄膜中铝的质量分数与薄膜电学性能和发光性能的关系。结果表明,掺杂铝的质量分数为1.37%时所获得的ZnO薄膜具有最小的电阻率和较强的紫外发光特性。     

Growth and characterization of indium doped zinc oxide films sputtered from powder targets

Indium doped Zn O films were grown on quartz glass substrates by radio frequency magnetron sputtering from powder targets. Indium content in the targets varied from 1at% to 9at%. In doping on the structure, optical and electrical properties of Zn O thin films were studied. X-ray diffraction shows that all the films are hexagonal wurtzite with c-axis perpendicular to the substrates. There is a positive strain in the films and it increases with indium content. All the films show a high transmittance of 86% in the visible light region. Undoped Zn O thin film exhibits a high transmittance in the near infrared region. The transmittance of indium doped Zn O thin films decreases sharply in the near infrared region, and a cut-off wavelength can be found. The lowest resistivity of 4.3×10~(-4) Ω·cm and the highest carrier concentration of 1.86×10~(21) cm~(-3) can be obtained from Zn O thin films with an indium content of 5at% in the target.     

Comprehensive optimization of electrical and optical properties for ATO films prepared by pulsed laser deposition

Antimony doped tin oxide(ATO) thin films have been prepared by pulsed laser deposition(PLD) method.The intrinsic effect of Sb dopant,including the Sb content,transition degree between Sb~(3+) and Sb~(5+) and crystallinity on the electrical and optical properties of the ATO thin films is mainly investigated.It is suggested that the transition degree of Sb~(3+) towards Sb~(5+)(Sb~(5+)/Sb~(3+) ratio) is determined by Sb content.When the Sb content is increased to 12 at%,the Sb~(5+)/Sb~(3+) ratio reaches the highest value of 2.05,corresponding to the resistivity of 2.70×10~(-3) Ω·cm.Meanwhile,the Burstein-Moss effect caused by the increase of carrier concentration is observed and the band gap of the ATO thin films is broadened to 4.0 eV when the Sb content is increased to 12 at%,corresponding to the highest average optical transmittance of 92%.Comprehensively considering the combination of electrical and optical properties,the ATO thin films deposited with Sb content of 12 at%exhibit the best properties with the highest "figure of merit" of 3.85×10~(-3) Ω~(-1).Finally,an antimony selenide(Sb_2Se_3) heterojunction solar cell prototype with the ATO thin film as the anode has been prepared,and a power conversion efficiency of 0.83%has been achieved.     

氧化锌薄膜的p型掺杂研究现状

ZnO薄膜作为一种多用途的光电材料,一直受到国内外学术界的广泛关注。为了开发ZnO短波长光电器件,首要解决的 关键问题是氧化锌的p型掺杂。综述了目前国际上常用的氧化锌p型掺杂方法,对不同方法制备的p型ZnO薄膜的性能进行了 分析比较。     

Al2O3掺杂对ZnO薄膜结构及光电性能的影响

以ZnAl2O4陶瓷靶为溅射源,采用射频磁控溅射法,利用优化的氧化锌薄膜制备工艺,在石英衬底上沉积了Al2O3掺杂ZnO（AZO）透明导电薄膜,并通过X射线衍射仪、紫外-可见分光光度计、薄膜测厚仪、霍尔效应仪对其进行了结构表征和光电性能测试,研究了靶材中Al2O3不同掺杂质量分数（1%~5%）对薄膜结构及光电性能的影响。结果表明：沉积所得AZO薄膜为六方形纤锌矿结构,沿（002）晶面择优取向生长;随着Al2O3掺杂比例的提高,薄膜禁带宽度先增大后减小,电阻率先减小后增大;当Al2O3掺杂质量分数为4%时,薄膜择优取向性最好,可见光透过率最高,电阻率最小,具有最优的结晶质量和光电性能。     

CdO - ZnO复合薄膜的光电学特性研究

采用磁控溅射技术制备了不同原子百分比的CdO - ZnO复合薄膜,并利用X射线衍射仪、扫描电子显微镜、紫外可见近红外分光光度计、四探针电阻测试仪研究了薄膜的结构和光电学特性.研究表明:适量增加CdO掺杂量可提高薄膜在近红外区域的透射率; CdO - ZnO复合薄膜的光学带隙和电阻率随CdO含量的增加而减小,且当CdO和ZnO的原子百分比为4:1时薄膜的带隙和电阻率分别为2.09 eV和10.79×10^-3 Ω·cm.该研究结果可为制备高导电性和高透过率的薄膜提供参考.     

梯度掺杂AZO薄膜的制备及其性能表征

采用Sol-Gel法,以不同铝离子浓度的溶胶梯度掺杂的方法制备了Al掺杂ZnO（AZO）薄膜,用XRD衍射仪和SEM扫描电镜对该薄膜进行了结构和形貌分析,并对其电学性能和光学性能进行了研究。结果表明,梯度掺杂的AZO薄膜比单一浓度掺杂5.0 at%（原子数百分比）的薄膜具有更明显的c轴择优取向,更强的本征紫外发光峰和近紫外发光峰。当薄膜的退火温度在500~650℃区间时,薄膜电阻率稳定在10-2Ω.cm,高于700℃时,薄膜电阻率明显升高。     

Effect of oxygen partial pressure on epitaxial growth and properties of laser-ablated AZO thin films

Al-doped ZnO (AZO) thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures (P _O2). The effect of PO2 on the crystal structure, preferred orientation as well as the electrical and optical properties of the films was investigated. The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure, showing a significant c-axis orientation. The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P _O2. At the optimum oxygen partial pressures of 10 - 15 Pa, the AZO thin films were epitaxially grown on c-sapphire substrates with the (0001) plane parallel to the substrate surface, i e, the epitaxial relationship was AZO (000 1) // Al₂O₃ (000 1). With increasing P _O2, the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly, which led to an enhancement in electrical conductivity of the AZO thin films. All the films were highly transparent with an optical transmittance higher than 85 %.     

Optical waveguide and nonlinear properties of Bi<Subscript>3</Subscript>NdTi<Subscript>3</Subscript>O<Subscript>12</Subscript> thin films

Neodymium-substituted bismuth titanate (Bi₃NdTi₃O₁₂, BNT) thin films were prepared on quartz substrates by a metal-organic solution deposition process. The crystalline structure was evaluated by X-ray diffraction. Waveguide property was investigated by using prism coupling technique and optical transmittance measurement. The optical nonlinearities of the film were measured by the top-hat Z-scan techniques and a large positive nonlinear refractive index, nonlinear refractive coefficient and two-photon absorption coefficient were determined to be 3.84 × 10⁻⁷ esu, 0.7523 cm²/GW and 4.81 × 10⁴ cm/GW, respectively. These results reveal that the BNT film may be a kind of new multifunctional materials.     

Graft Polymerization of Acrylic Acid and Acrylamide onto BOPET Corona Films

1　IntroductionBOPETfilmsaremoreandmorewidelyusedinagri culture,packing ,electricityandsoonfortheirexcellentproperty[1 ] .ButthefurtherapplicationsofBOPETfilmsarelimitedinprintingplating ,adhesionetcduetotheirlowersurfacepolarity ,hydrophobicpropertyandpo…     

Effect of the sputtering parameters on the structure and properties of Cu<Subscript>3</Subscript>N thin film materials

Copper nitride (Cu₃N) thin films were successfully deposited on glass substrates by reactive radio frequency magnetron sputtering. The effects of sputtering parameters on the structure and properties of the films were studied. The experimental results show that with increasing of RF power and nitrogen partial pressure, the preferential crystalline orientation of Cu₃N film is changed from (111) to (100). With increasing of substrate temperature from 70 °C to 200 °C, the film phase is changed from Cu₃N phase to Cu. With increasing sputtering power from 80 W to 120 W, the optical energy decreases from 1.85 eV to 1.41 eV while the electrical resistivity increases from 1.45 ×10² Ω · cm to 2.99 × 10³ Ω · cm, respectively.     

Influence of argon gas pressure on the ZnO:Al films deposited on flexible TPT substrates at room temperature by magnetron sputtering

Aluminium doped ZnO thin films(ZnO︰Al) were deposited on transparent polymer substrates at room temperature by rf magnetron sputtering method from a ZnO target with Al2O3 of 2.0 wt%. Argon gas pressure varied from 0.5 Pa to 2.5 Pa with radio frequency power of 120 W. XRD results showed that all the ZnO︰Al films had a polycrystalline hexagonal structure and a (002) preferred orientation with the c-axis perpendicular to the substrate. The grain sizes of the films were 6.3-14.8 nm.SEM images indicated the ZnO︰Al film with low Argon gas pressure was denser and the deposition rate of the films depended strongly on the Argon gas pressure, increasing firstly and then decreasing with increasing the pressure. The highest deposition rate was 5.2 nm/min at 1 Pa. The optical transmittance of the ZnO︰Al films increased and the blue shift of the absorption edge appeared when the Argon gas pressure increased. The highest transmittance of obtained ZnO︰Al films at 2.5 Pa was about 85% in the visible region. The electrical properties of the films were worsened with the increase of the Argon gas power from 1 Pa to 2.5 Pa. The resistivity of obtained film at 1.0 Pa was 2.79×10-2 Ω·cm.     

Study on pulsed laser ablation and deposition of ZnO thin films by L-MBE

ZnO,as a wide-band gap semiconductor,has recently become a new research fo-cus in the field of ultraviolet optoelectronic semiconductors. Laser molecular beam epitaxy(L-MBE) is quite useful for the unit cell layer-by-layer epitaxial growth of zinc oxide thin films from the sintered ceramic target. The ZnO ceramic target with high purity was ablated by KrF laser pulses in an ultra high vacuum to deposit ZnO thin film during the process of L-MBE. It is found that the deposition rate of ZnO thin film by L-MBE is much lower than that by conventional pulsed laser deposition(PLD) . Based on the experimental phenomena in the ZnO thin film growth process and the thermal-controlling mechanism of the nanosecond(ns) pulsed laser abla-tion of ZnO ceramic target,the suggested effective ablating time during the pulse duration can explain the very low deposition rate of the ZnO film by L-MBE. The unique dynamic mechanism for growing ZnO thin film is analyzed. Both the high energy of the deposition species and the low growth rate of the film are really beneficial for the L-MBE growth of the ZnO thin film with high crystallinity at low temperature.     

射频磁控溅射制备的CdSe薄膜的光电学性质

采用射频磁控溅射技术在不同溅射功率下制备了CdSe薄膜,并利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量色散X射线光谱仪(EDAX)、紫外可见近红外(UV-VIS-NIR)分光光度计和霍尔效应测试仪研究了溅射功率对薄膜的结构和光电学性质的影响.研究表明：增加溅射功率有利于增强薄膜的结晶性能;随着溅射功率的增加,薄膜的光学带隙和电阻率逐渐减小,载流子浓度逐渐增加,即薄膜的光电性能不断增强.该研究结果可为CdSe薄膜在光电器件方面的应用提供参考.     

氧氩比和退火温度对AZO薄膜结构与性能的影响

在通氩气和不同比率氧氩混合气体的条件下,利用射频磁控溅射法在玻璃衬底上制备铝(Al)掺杂氧化锌(AZO)薄膜(溅射功率为180W,衬底温度为300℃),并对部分薄膜样品进行400℃或500℃退火处理.采用X射线衍射仪(XRD)、原子力显微镜(AFM)和分光光度计对薄膜的结构、表面形貌和光学性能进行测试研究.结果表明,制备的所有薄膜均呈现(002)晶面择优生长;与氩气溅射相比,当采用氧氩混合气体溅射时,生长的AZO薄膜晶粒尺寸显著增大;退火处理使2类薄膜的表面粗糙度都明显减小,晶粒也有所增大(7%~13%).其中,在氧氩比为1∶2的混合气体中制备的薄膜,经过500℃退火后,晶粒尺寸最大(39.4nm),薄膜表面更平整致密,在可见光区平均透过率接近最大(89.3%).     

Preparation,characterization and electronic properties of fluorine-doped tin oxide films

Tin oxide(SnO_2) and fluorine doped tin oxide(FTO) films were prepared on glass substrates by sol-gel spin-coating using SnCl_4 and NH_4F precursors.Fluorine doping concentration was fixed at 4 at%and 20 at%by controlling precursor sol composition.Films exhibited the tetragonal rutile-type crystal structure regardless of fluorine concentration.Uniform and highly transparent FTO films,with more than 85%of optical transmittance,were obtained by annealing at 600℃.Florine doping of films was verified by analyzing the valence band region obtained by XPS.It was found that the fluorine doping affects the shape of valence band of SnO_2 films.In addition,it was observed that the band gap of SnO_2 is reduced as well as the Fermi level is upward shifted by the effect of fluorine doping.     

锡掺杂氧化锌薄膜乙醇气敏性的研究

以载玻片为基片,依次采用溶胶凝胶、浸渍提拉和热处理方法制备掺杂锡的氧化锌薄膜气敏材料.分别采用红外光谱对氧化锌溶胶体系进行表征;扫描电子显微镜(SEM)观察氧化锌薄膜的表面形貌;主要利用电化学工作站测量极限电流与乙醇气体浓度的关系,研究掺杂氧化锡的氧化锌薄膜在常温下的乙醇气敏性能.结果表明:所成溶胶体系稳定;10层锡掺杂氧化锌薄膜晶型较完整,排列有序,在常温条件下乙醇气体含量为0～500μL/L时,极限电流与气体浓度呈现较好的线性关系;在乙醇气体含量为500μL/L时,灵敏度可高达82.39.     

Er^＋注入Yb掺杂的ZnO波导膜的光学及结构特性研究

利用射频磁控溅射技术在蓝宝石衬底上沉积ZnO：Yb光波导薄膜,然后用离子注入技术将能量为200keV的Er^＋离子注入薄膜中,剂量为1×10^15ions／cm2。应用棱镜耦合技术、卢瑟福背散射（RBS）技术、X射线衍射（XRD）技术和荧光光谱等技术研究了薄膜的波导性质、基本结构、厚度、组分、Er^＋的射程情况及光学频率上转换性质。实验发现掺杂Yb和Er的薄膜可以形成光波导结构,但波导质量较纯ZnO波导膜差,膜的有效折射率及沉积速率随Yb掺杂量增加有减小趋势;薄膜呈ZnO高度c-轴取向生长,Yb和Er能有效掺杂进ZnO晶格,ZnO晶格常数受Yb掺杂量的不同而变化;在980nm激光激发下没有发现在300-720nm间的光学频率上转换。     

Remarkable improvement of ferroelectric properties and leakage current in BiFeO<Subscript>3</Subscript> thin films by nd modification

Ferroelectric and leakage properties are important for ferroelectric applications. Pure and Nd-doped (x=0.05-0.20) BiFeO3 thin films were fabricated by sol-gel method on FTO substrates. The phase structure, surface morphology, leakage current, ferroelectric properties, and optical properties of BiFeO₃^- based thin films were investigated. The substitution of Nd³⁺ ions for the Bi3+ site converts the structure from rhombohedral to coexisting tetragonal and orthorhombic. Nd doping improves the crystallinity of BiFeO₃ thin films. The leakage current of Nd-doped BiFeO₃ decreases by two to three orders of magnitude compared with that of pure BiFeO₃. Among the samples, 15% Nd-doped BiFeO₃ exhibits the strongest ferroelectric polarization of 17.96 μC/cm². Furthermore, the absorption edges of Bi_1-xNd _x FeO₃ thin films show a slight red-shift after Nd doping.