不同缓冲层对Al掺杂ZnO薄膜性能的影响

本文采用射频反应磁控溅射法在玻璃基底上分别以Al2O3和AZO为缓冲层制备ZnO:Al(AZO)薄膜,利用X射线衍射仪(XRD)、扫描电镜(SEM)、紫外-可见分光光度计等方法对薄膜的结构和光电性能进行表征。XRD和SEM的分析结果表明,在Al2O3和AZO缓冲层上生长的AZO薄膜均具有较好的C轴择优取向,薄膜表面光滑平整,薄膜的结晶质量得到改善;透射光谱表明所有样品在可见光范围内的透过率均超过80%;薄膜的导电性能得到提高。     

ZnO缓冲层上低温生长Al掺杂的ZnO薄膜

采用射频磁控溅射法在ZnO缓冲层上制备了不同Al掺杂量的ZnO（AZO）薄膜。利用X射线衍射（XRD）、扫描电子显微镜（SEM）和光致发光（PL）等表征技术,研究了AZO薄膜的微观结构、表面形貌和发光特性。结果表明,随着Al掺杂量的增加,ZnO薄膜的择优取向性发生了改变,且当Al的掺杂量为0.81%（原子分数）时,（002）衍射峰与其它衍射峰强度的比值达到最大,表明适合的Al掺杂使ZnO薄膜的择优取向性得到了改善。在可见光范围内薄膜的平均透过率超过70%。通过对样品光致发光（PL）谱的研究,发现所有样品出现了3个发光峰,分别对应于以444nm（2.80eV）、483nm（2.57eV）为中心的蓝光发光峰和以521nm（2.38eV）为中心较弱的绿光峰。并对样品的发光机理进行了详细的探讨。     

掺铝氧化锌透明导电薄膜的表面织构研究

利用中频直流磁控反应溅射法在玻璃衬底上首先制备了掺铝氧化锌(AZO)透明导电薄膜,然后利用5%的氯化铵(NH4Cl)溶液对制备的AZO薄膜进行表面织构。利用扫描电子显微镜(SEM)、四探针法和分光光度计分别测量并研究了织构前后薄膜的表面形貌、电学和光学特性。研究结果表明NH4Cl水溶液容易控制AZO的表面织构过程,并且可以获得较好的绒面。表面织构后,薄膜在可见光波段的平均反射率从12%降低到7.86%,而电阻率略有增大,该结果和表面织构结果一致。     

溅射气压对直流磁控溅射ZnO:Al薄膜的影响(英文)

采用直流磁控溅射法在玻璃基片上沉积ZnO:Al(AZO)薄膜,溅射气压为0.2～2.2 Pa.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、四探针和紫外–可见分光光度计对AZO薄膜的相结构、微观形貌和电光学性质进行了表征.结果表明:薄膜的沉积速率随着溅射气压的增大而减小,变化曲线符合Keller-Simmons模型;薄膜均为六角纤锌矿结构,但择优取向随着溅射气压发生改变;溅射气压对薄膜的表面形貌有显著影响;当溅射气压为1.4 Pa时,薄膜有最低的电阻率(8.4×104 Ω·cm),高的透过率和最高的品质因子Q.     

Structural and nonlinear optical behavior of Ag-doped ZnO films

We present the structural and nonlinear optical behavior of Ag-doped ZnO (AZO) films prepared by magnetron sputtering. The structural of AZO films are systematically investigated by X-ray diffraction (XRD) and scanning electronic microscopy (SEM), respectively. The results show that AZO films can still retain a wurtzite structure, although the c-axis as preferred orientation is decreased by Ag doping. As the amounts of the Ag dopant were increased, the crystallinity as well as the absorptivity and optical band gap were increased. Moreover, the nonlinear optical characterized of the AZO films was studied using Z-scan technique. These samples show self-defocusing nonlinearity and good nonlinear absorption behavior which increases with increasing Ag volume fraction. AZO is a potential nanocomposite material for the development of nonlinear optical devices with a relatively small limiting threshold.     

射频溅射工艺参数对AZO薄膜结构和性能的影响

采用射频磁控溅射法制备了掺铝氧化锌(AZO)薄膜,研究了衬底温度及溅射工作压强对沉积薄膜的晶体结构、表面形貌及电学性能的影响。结果显示,随衬底温度增加,薄膜的结晶结构发生显著变化,而溅射工作气压增加主要影响沉积薄膜(103)面与(002)面的相对强度。薄膜的表面形貌受温度影响严重,而气压对形貌的影响相对较小。衬底温度增加,薄膜的电阻率急剧降低,迁移率和载流子浓度都显著增加,而工作气压增加则导致电阻率先减小后增大。     

透明导电AZO/Cu双层薄膜制备及其性能

采用直流磁控溅射方法在玻璃衬底上室温生长了AZO/Cu双层薄膜,Cu层厚度控制在9nm,研究了AZO层厚度对薄膜电学和光学性能的影响。当AZO层厚度为20～80nm时,AZO/Cu双层薄膜具有良好的综合光电性能,方块电阻为12～14Ω/sq,可见光平均透过率为70～75%,品质因子为2×10-3～5×10-3Ω-1。AZO/Cu双层薄膜可以观察到Cu（111）和ZnO（002）的XRD衍射峰。通过退火研究表明,AZO/Cu双层薄膜的光电性能可在400℃下保持稳定,具有良好的热稳定性。本研究制备的透明导电AZO/Cu双层薄膜具有室温制程、综合光电性能良好、结晶性能较好、稳定性高的优点,可以广泛应用于光电器件透明电极及镀膜玻璃等领域。     

Effect of Enhanced Plasma Density on the Properties of Aluminium Doped Zinc Oxide Thin Films Produced by DC Magnetron Sputtering

Aluminum doped zinc oxide (AZO) thin films were prepared by DC magnetron sputtering at low substrate temperature. A coaxial solenoid coil was placed near the magnetron target to enhance the plasma density (Ji). The enhanced plasma density improved significantly the bulk resistivity (ρ) and its homogeneity in spatial distribution of AZO films. X-ray diffraction (XRD) analysis revealed that the increased Ji had inuenced the crystallinity, stress relaxation and other material properties. The AZO films deposited in low plasma density (LPD) mode showed marked variation in ρ (ranging from ～6.5×10?2 to 1.9×10-3 ·cm), whereas those deposited in high plasma density (HPD) mode showed a better homogeneity of films resistivity (ranging from ～1.3×10?3 to 3.3×10?3 ?·cm) at di?erent substrate positions. The average visible transmittance in the wavelength range of 500-800 nm was over 80%, irrespective of the deposition conditions. The atomic force microscopy (AFM) surface morphology showed that AZO films deposited in HPD mode were smoother than that in LPD mode. The high plasma density produced by the coaxial solenoid coil improved the electrical property, surface morphology and the homogeneity in spatial distribution of AZO films deposited at low substrate temperature.     

Characterization of crystalline structure and morphology of NiO thin films

We investigated the relation of sputtering powers with structural and morphological properties of nickel oxide (NiO) thin films. NiO thin films were fabricated by using an rf-reactive sputtering method on Si(100) substrates with a Ni target in a partial pressure of oxygen and argon. The films were deposited by various rf-sputtering powers from 100 to 200 W at room temperature. The phases and crystalline structures of the deposited films were investigated by using grazing incident X-ray diffraction (XRD). The thickness and surface morphology of the films were investigated by using a field emission-scanning electron microscopy (FE-SEM). The different sputtering conditions drastically affected the crystallinity and the surface morphology of NiO thin films. A combined analysis of the data obtained from X-ray diffraction and SEM images demonstrates that the preferred orientation of NiO films tends to grow from (111) to (200) direction as increasing the sputtering power, which can be explained by in terms of the surface energy along the indexing plane in an fcc structure. As increasing the rf power, lattice constants decreased from 4.26 to 4.20 angstroms and samples became high-quality crystals. Under our experimental condition, NiO films prepared at 150 W with 20% partial pressure of oxygen and 7 cm distance from the sample to the target show the best quality of the crystal.     

溅射功率对AZO透明导电薄膜的影响

采用射频磁控溅射法在玻璃衬底上沉积了AZO透明导电薄膜,并用原子力显微镜观测了薄膜表面形貌,XRD测试了薄膜相结构和单色仪测试了薄膜透射率。结果表明,制备的薄膜具有高度c轴择优取向性,其表面平整,晶粒均匀致密。当溅射功率为180W、溅射气体流量为15sccm、基片温度为200℃时制得的薄膜方阻为10Ω/□,在可见光区平均透射率大于85%。     

Effects of substrate temperatures on the thermal stability of Al-doped ZnO thin films grown by DC magnetron sputtering

In this work, Al-doped (4 at%) ZnO(AZO) thin films were prepared by DC magnetron sputtering using a home-made ceramic target at different substrate temperatures. The microstructure, optical, electrical and thermal stability properties of these thin films were characterized systematically using scanning electron microscopy, UV–Vis-NIR spectrometry, X-ray diffraction, and Hall measurements. It was observed that the AZO thin films deposited at 350 °C exhibited the lowest resistivity of 5.76 × 10⁻⁴ Ω cm, high average visible transmittance (400–800 nm) of 92%, and the best thermal stability. Comparing with the AZO thin films deposited at low substrate temperatures, the AZO thin films deposited at 350 °C had the highest compact surface morphology which could hinder the chemisorbed and diffused oxygen. This was considered to be the main mechanism which was responsible for the thermal degradation of AZO thin films.     

室温下射频磁控溅射制备ZnO:Al透明导电薄膜及其性能研究

采用射频磁控溅射技术,在室温下,以ZnO:Al2O3(2%Al2O3(质量比))为靶材,在石英玻璃基底上,采用不同工艺条件制备了ZnO:Al(AZO)薄膜。使用扫描电子显微镜观察了薄膜的表面形貌,X射线衍射分析了薄膜的结构,四探针测量仪得到薄膜的表面电阻,轮廓仪测量了薄膜厚度,并计算了电阻率,最后采用分光光度计测量了薄膜的透过率;研究了溅射功率、溅射气压与薄膜厚度对薄膜电阻率及透过率的影响。结果表明:所制备的AZO薄膜具有(002)择优取向,并且发现薄膜厚度对薄膜的光电性能有明显影响,溅射气压和溅射功率对薄膜电学性能有较大影响,但是对薄膜透过率影响不大。当功率为1kW、溅射气压0.052Pa、AZO薄膜厚度为250nm时,其电阻率为8.38×10-4Ω·cm,波长在550nm处透过率为89%,接近基底的本底透过率92%。当薄膜厚度为1125 nm时薄膜的电阻率降至最低(6.16×10-4Ω·cm)。     

Structural, optical and electrical properties of AZO/Cu/AZO tri-layer films prepared by radio frequency magnetron sputtering and ion-beam sputtering

Highly conducting tri-layer films consisting of a Cu layer sandwiched between Al-doped ZnO (AZO) layers (AZO/Cu/AZO) were prepared on glass substrates at room temperature by radio frequency (RF) magnetron sputtering of AZO and ion-beam sputtering of Cu. The tri-layer films have superior photoelectric properties compared with the bi-layer films (Cu/AZO, AZO/Cu) and single AZO films. The effect of AZO thickness on the properties of the tri-layer films was discussed. The X-ray diffraction spectra show that all films are polycrystalline consisting of a Cu layer with the cubic structure and two AZO layers with the ZnO hexagonal structure having a preferred orientation of (0 0 2) along the c-axis, and the crystallite size and the surface roughness increase simultaneously with the increase of AZO thickness. When the AZO thickness increases from 20 to 100 nm, the average transmittance increases initially and then decreases. When the fixed Cu thickness is 8 nm and the optimum AZO thickness of 40 nm was found, a resistivity of 7.92 × 10⁻⁵ Ω cm and an average transmittance of 84% in the wavelength range of visible spectrum of tri-layer films have been obtained. The merit figure (F_TC) for revaluing transparent electrodes can reach to 1.94 × 10⁻² Ω⁻¹.     

Effect of Cu layer thickness on the structural, optical and electrical properties of AZO/Cu/AZO tri-layer films

Highly conducting AZO/Cu/AZO tri-layer films were successfully deposited on glass substrates by RF magnetron sputtering of Al-doped ZnO (AZO) and ion-beam sputtering of Cu at room temperature. The microstructures of the AZO/Cu/AZO multilayer films were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and atomic force microscope (AFM). X-Ray diffraction measurements indicate that the AZO layers in the tri-layer films are polycrystalline with the ZnO hexagonal structure and have a preferred orientation with the c-axis perpendicular to the substrates. With the increase of Cu thickness, the crystallinity of AZO and Cu layers is simultaneously improved. When the Cu thickness increases from 3 to 13 nm, the resistivity decreases initially and then varies little, and the average transmittance shows a first increase and then decreases. The maximum figure of merit achieved is 1.94 × 10⁻² Ω⁻¹ for a Cu thickness of 8 nm with a resistivity of 7.92 × 10⁻⁵ Ω cm and an average transmittance of 84%.     

Sol–gel and rf sputtered AZO thin films: analysis of oxidation kinetics in harsh environment

Al-doped ZnO (AZO) thin film, which possess the advantages of low cost, low sheet resistance and high transmittance, are one of the most promising candidates to replace indium tin oxide films as the transparent electrode. However, oxidation causes a substantial increase in the sheet resistance of AZO film after exposing in ambient and especially, damp heat environment. In this work, we compare structural, optical, electrical properties and environmental stability between films prepared by two different methods: sol–gel and rf sputtering. Experimental results indicate that the properties of film can be affected by different deposition method. From the X-ray diffraction analysis, all films have hexagonal wurtzite crystal structure with different preferable orientation in two different methods. Optical transmittance spectra of the AZO films exhibited transparency higher than about 80 % within the visible wavelength region and the optical band gap (E_g) of these films was increased in sputtered film, probably due to the increase of carrier concentration. The better environmental stability was found in AZO film prepared by sputtering method. Improved surface morphology and enhancement of crystal orientation (110) was considered for this improvement.     

Effects of annealing and deposition temperature on the structural and optical properties of AZO thin films

Al-doped ZnO (AZO) thin films were deposited on p- type Si(100) substrate by r.f magnetron sputtering at 200, 300 and 400 °C substrate temperatures. The deposited films were annealed in air atmosphere for 1 h at temperatures of 700, 800 and 900 °C. The deposition temperature and post-deposition annealing effects on structural and optical properties of the AZO samples were analyzed using X-ray diffraction, atomic force microscope and photoluminescence (PL). After annealing, the value of full width half maximum of the diffraction peaks was decreased as well as, the intensity of visible and strong UV PL emission peaks were increased with temperature. However, the deep-level emission related with zinc point defects was removed by annealing of the samples. Results revealed that all of the as-deposited and annealed AZO films have hexagonal structure along (002) direction and their crystallinity were improved with the increased deposition and post-growth annealing temperatures. In addition, the surface roughness and the particle size of the films were increased with increased deposition and annealing temperatures.     

The effect of annealing on Al-doped ZnO films deposited by RF magnetron sputtering method for transparent electrodes

In this study, transparent conducting Al-doped zinc oxide (AZO) films with a thickness of 150 nm were prepared on Corning glass substrates by the RF magnetron sputtering with using a ZnO:Al (Al₂O₃: 2 wt.%) target at room temperature. This study investigated the effects of the post-annealing temperature and the annealing ambient on the structural, electrical and optical properties of the AZO films. The films were annealed at temperatures ranging from 300 to 500 °C in steps of 100 °C by using rapid thermal annealing equipment in oxygen. The thicknesses of the films were observed by field emission scanning electron microscopy (FE-SEM); their grain size was calculated from the X-ray diffraction (XRD) spectra using the Scherrer equation. XRD measurements showed the AZO films to be crystallized with strong (002) orientation as substrate temperature increases over 300 °C. Their electrical properties were investigated by using the Hall measurement and their transmittance was measured by UV-vis spectrometry. The AZO film annealed at the 500 °C in oxygen showed an electrical resistivity of 2.24 × 10^− 3 Ω cm and a very high transmittance of 93.5% which were decreased about one order and increased about 9.4%, respectively, compared with as-deposited AZO film.     

TiO_2过渡层对Si基ZnO薄膜光致发光特性的影响

采用直流反应溅射法在Si(100)衬底上制备了有TiO2过渡层的ZnO薄膜,并与直接在Si上生长的样品进行比较。通过X射线衍射技术和光致发光谱等分别对ZnO薄膜的结构和光学性质进行测量和分析。测量结果表明,引入过渡层后ZnO薄膜的平均晶粒尺寸变大,晶粒间界变少,结晶质量提高,薄膜内的应力得到一定程度的释放。此外,室温光致发光谱表明过渡层使ZnO薄膜的紫外发射明显增强,并研究和分析了其微观机理。     

Low-temperature growth of highly c-oriented InN films on glass substrates with ECR-PEMOCVD

High quality InN films are deposited with an interlayer of high c-orientation (002) AZO (Aluminium-doped Zinc Oxide; ZnO:Al) films on glass substrates by electron cyclotron resonance plasma-enhanced metal organic chemical vapor deposition (ECR-PEMOCVD) at low temperature. AZO films used as a buffer layer are effective for the epitaxial growth of InN films. The influence of Trimethyl Indium (TMIn) flux on the properties of InN films is systematically investigated by reflection high energy electron diffraction (RHEED), X-ray diffraction analysis (XRD), atomic force microscopy (AFM) and optical transmittance spectra. The results indicate that high quality InN films with high c-orientation and small surface roughness are successfully achieved at an optimized Trimethyl Indium (TMIn) flux of 5.5 sccm. The InN/AZO structures have great potential for the development of full spectra solar cells.     

ZnO∶Al薄膜制备及光电性能研究

利用溶胶-凝胶法在玻璃基板上制备了Al/Zn原子掺杂比例为0～0.25的掺铝氧化锌(ZnO∶Al或AZO)薄膜,随后分别将其在空气,氧气和氮气3种不同气氛中退火处理,研究了薄膜的光学、电学与结构方面的性质.X射线衍射分析表明AZO薄膜是具有c轴择优取向的六方纤锌矿结构多晶体;通过紫外-可见光分光计测定表明该薄膜在可见光范围内具有>80%的高透过率,随着铝掺杂比例的增大光学能隙增大且吸收边向短波方向移动.