粉末靶制备的AZO/Ag/AZO透明导电薄膜的光电性能

室温下,采用射频磁控溅射AZO粉末靶和Ag靶在玻璃基底上制备Ag层厚度分别为12 nm和15 nm两组对称结构掺铝氧化锌/银/掺铝氧化锌(AZO/Ag/AZO)透明导电薄膜,研究了Ag层和AZO层厚度对薄膜光电性能的影响。结果表明:3层薄膜的可见光区平均透光率达到了80%,550 nm处的最高透过率达到了88%,方块电阻小于5 Ω/□。Ag层厚度是影响AZO/Ag/AZO薄膜光电性能的主要因素,AZO层的厚度对薄膜光学性能影响较大。     

用粉末靶在玻璃和PI衬底上制备AZO/Ag/AZO薄膜

室温下在玻璃和聚酰亚胺两种不同衬底上, 采用射频磁控溅射法溅射掺铝氧化锌(AZO)粉末靶和固体Ag靶, 制备了两组AZO/Ag/AZO 3层透明导电薄膜, 研究了AZO层厚度对不同衬底3层膜结构和光电性能的影响.结果表明:不同衬底的两组AZO/Ag/AZO薄膜均为多晶膜.当Ag层厚度不变时, 随着AZO层厚度的增加, 两组薄膜电学性能变化不大, 透射峰向长波方向移动.玻璃和PI衬底上制备的AZO(30 nm)/Ag(14 nm)/AZO(30 nm)薄膜, 在550 nm处的透光率分别为85%和70%, 方块电阻分别为2.6 Ω/□和4.6 Ω/□.     

H2 气对脉冲磁控溅射铝掺杂氧化锌薄膜性能的影响

实验采用脉冲磁控溅射法制备铝掺杂氧化锌(AZO)薄膜.为了进一步提高AZO薄膜的光电性能,在溅射过程中加入一定流量的氢气,以高纯ZnO ∶Al₂O₃陶瓷靶为溅射靶材,制备AZO/H透明导电薄膜.通过测试薄膜的结构特性、表面形貌及其光电性能,详细地研究了氢气流量对AZO薄膜性能的影响.溅射过程中引入氢气,可以促进薄膜的晶化,提高薄膜的迁移率和透过率(400—1100 nm).采用纯氩气溅射制备AZO薄膜的电阻率为5.664×10^-4 Ω·cm 关键词： 氧化锌 氢气流量 磁控溅射 太阳电池     

基于金属掺杂ITO透明导电层的紫外LED制备

为降低ITO薄膜对紫外波段的光吸收,制备低电压高功率的紫外LED,研究了一种基于金属掺杂ITO透明导电层的365 nm紫外LED的制备工艺。利用1 cm厚的石英片生长了不同厚度ITO薄膜以及在ITO上掺杂不同金属的新型薄膜,并研究了在不同的退火条件下这种薄膜的电阻和透过率,分析了掺杂金属ITO薄膜的带隙变化。将这种掺杂的ITO薄膜生长在365 nm外延片上并完成电极生长,制备成14 mil×28 mil的正装LED芯片。利用电致发光（EL）设备对LED光电性能进行测试并对比。实验结果表明:掺Al金属的ITO薄膜能够相对ITO薄膜的带隙提高0.15 eV。在600℃退火后,方块电阻降低6.2 Ω/□,透过率在356 nm处达到90.8%。在120 mA注入电流下,365 nm LED的电压降低0.3 V,功率提高14.7%。ITO薄膜掺金属能够影响薄膜带隙,改变紫光LED光电性能。     

基于AZO/VO_2/AZO结构的电压诱导相变红外光调制器

采用直流磁控溅射和后退火工艺先在掺Al氧化锌(AZO)导电玻璃基底上制备了高质量的VO_2薄膜,再在VO_2膜层上制备AZO导电膜,最终制备出了AZO/VO_2/AZO三明治结构.测试了VO_2/AZO复合薄膜和AZO/VO_2/AZO三明治结构的组分、微结构以及光学特性,结果表明VO_2/AZO复合薄膜在800—2300 nm红外区域其相变前后的最大透过率差值达24%,而AZO/VO_2/AZO三明治结构在相同波长范围内其相变前后的最大透过率差值可达31%.通过在AZO/VO_2/AZO三明治结构导电膜层上施加不同电压,观察到不同外界温度下电流的突变,当外界温度越高,所需阈值电压越低.AZO/VO_2/AZO三明治结构性能稳定,制备工艺简单,有望应用于集成式红外光调制器.     

生长条件对脉冲激光沉积制备ZnO：Al薄膜光电性能的影响

本文研究了脉冲激光沉积(PLD)生长过程中, 铝掺量、氧压及衬底温度等实验参数对ZnO:Al(AZO)薄膜生长的影响, 并利用扫描电子显微镜、原子力显微镜、X射线衍射、霍尔效应、光透射光谱等实验手段对其透明导电性能进行了探讨. 变温霍尔效应和光透射测量表明, 当靶材中铝掺量大于0.5 wt%时, 所制备AZO薄膜中铝施主在80 K时已完全电离, 因Bernstein-Moss (BM) 效应其带隙变大, 均为重掺杂简并半导体. 进一步系统研究了氧压和衬底温度对AZO薄膜透明导电性能的影响, 实验发现当氧压为1 Pa, 衬底温度为200 ℃时, AZO 导电性能最好, 其霍尔迁移率为28.8 cm²/V·s, 薄膜电阻率最小可达2.7×10^-4 Ω·cm, 且在可见光范围内光透过率超过了85%. 氧压和温度的增加, 都会导致薄膜电阻率变大. 关键词： 脉冲激光沉积法 ZnO：Al薄膜 透光性 导电性     

外加磁场对射频磁控溅射制备铝掺杂氧化锌薄膜影响的研究

利用射频磁控溅射法制备了铝掺杂氧化锌(AZO)透明导电薄膜,在传统的磁控溅射系统中引入外加磁场,研究了外加磁场对AZO薄膜沉积速率、形貌结构及光电特性的影响.研究结果表明,外加磁场后薄膜的沉积速率从不加磁场的13.04 nm/min提高到了19.93 nm/min;外加磁场后薄膜表面平整致密、颗粒大小均匀,结晶质量较高,而不加磁场薄膜表面形貌呈蠕虫状,薄膜质量较差.溅射时间为90 min时,外加磁场前后AZO薄膜方阻分别为30.74?/和12.88?/.外加磁场对薄膜可见光透过率影响不大,但使薄膜的吸收边蓝移现象更明显.运用ansys软件对磁控溅射二维磁场分布模拟后发现,外加磁场提高了靶上方横向磁场强度,改善了磁场分布的均匀性,加强了磁场对电子的磁控作用,提高了靶电流,是AZO薄膜的溅射速率、光电性能和形貌结构得到提高和优化的原因.     

基于铝浸润层的超薄银透明导电薄膜研究北大核心CSCD

超薄银薄膜具有高柔韧性和优良的光电性能,是用于透明导电电极的潜在材料。通过电阻热蒸发技术以金属铝作为浸润层制备超薄银透明导电薄膜。引入铝浸润层降低银薄膜的阈值厚度,使银薄膜在K9玻璃基底上以尽可能低的厚度达到连续。对不同厚度铝浸润层上银薄膜方块电阻进行测试,经SEM图像验证后得出,1 nm铝浸润层对银薄膜具有较好的浸润效果。随后采用相同的工艺在1 nm铝浸润层上制备了不同厚度的银薄膜,透过率和方阻测试结果表明,1 nm铝浸润层上制备的10 nm银薄膜方阻值可达到13Ω/,其在0.4μm~2.5μm波段内透过率可达到50%以上。     

Sr-F共掺杂的SnO2基透明导电薄膜

利用离子源辅助的电子束热蒸发技术研制了高性能的Sr-F共掺杂SnO2( SFTO)基透明导电薄膜。所制备的SFTO薄膜具有良好的导电性和透过率,电阻率低于3.9×10-3Ω·cm,380~2500 nm波段的平均透过率大于85%,功函数约为5.10 eV。 SFTO透明导电薄膜为非晶态薄膜,具有较好的表面平整度( Rq <1.5 nm)。与工业上F掺杂SnO2薄膜的衬底温度(>450℃)相比,本文所用的衬底温度仅为300℃,有望直接将SnO2基透明导电非晶薄膜制备到柔性的塑料( PI、PAR或PCO)衬底上以获得性能良好的柔性电极。     

VO_2/AZO复合薄膜的制备及其光电特性研究

采用直流磁控溅射和后退火氧化的方法在掺铝氧化锌(AZO)导电玻璃上制备了二氧化钒(VO2)薄膜,研究了不同的退火温度、退火时间对VO2/AZO复合薄膜制备的影响,并对复合薄膜的结构、组分、光电特性进行了测试与分析.结果表明,导电玻璃上的AZO没有改变VO2的取向生长,但明显改变了VO2薄膜的表面形貌特征.与用相同工艺和条件在普通玻璃基底上制备的VO2薄膜相比,VO2/AZO复合薄膜的相变温度降低约25?C,热滞回线宽度收窄至6?C,相变前后可见光透过率均在50%以上,1500 nm处红外透过率约为55%和21%,电阻率变化达3个数量级.该复合薄膜表面平滑致密,制备工艺简单,性能稳定,可应用于新型光电器件.     

Enhanced light extraction of GaN-based light-emitting diodes with periodic textured SiO_2 on Al-doped ZnO transparent conductive layer

We report an effective enhancement in light extraction of Ga N-based light-emitting diodes(LEDs) with an Al-doped Zn O(AZO) transparent conductive layer by incorporating a top regular textured SiO_2 layer. The 2 inch transparent throughpore anodic aluminum oxide(AAO) membrane was fabricated and used as the etching mask. The periodic pore with a pitch of about 410 nm was successfully transferred to the surface of the SiO_2 layer without any etching damages to the AZO layer and the electrodes. The light output power was enhanced by 19% at 20 m A and 56% at 100 m A compared to that of the planar LEDs without a patterned surface. This approach offers a technique to fabricate a low-cost and large-area regular pattern on the LED chip for achieving enhanced light extraction without an obvious increase of the forward voltage.     

Deposition of Ni, Ag, and Pt-based Al-doped ZnO double films for the transparent conductive electrodes by RF magnetron sputtering

Ni, Ag, and Pt-based Al-doped ZnO (AZO) films have been deposited as transparent conductivity layers on quartz by RF magnetron sputtering and characterized by X-ray diffraction, Hall measurement, optical transmission spectroscopy, scanning electron microscopy (SEM). The deposition of thicker metal layer in double layers resulted in lowering the effective electrical resistivity with a slight reduction of their optical transmittance. A film consisting of AZO (250 nm)/Ni (2 nm) double structure, exhibits a sheet resistance of 21.0 Ω/sq, a high transmittance of 76.5%, and characterize good adhesion to substrate. These results make the satisfactory for GaN-based light-emitting diodes (LEDs) and solar cells with metal-based AZO double films as current spread layers.     

p-GaN插入层调控InGaN基黄绿双波长LED发光光谱

采用MOCVD技术在硅衬底上生长了含有7个黄光量子阱和1个绿光量子阱的混合有源区结构的InGaN基黄绿双波长LED外延材料,研究了电子阻挡层前p-GaN插入层厚度对黄绿双波长LED载流子分布及外量子效率(EQE)的影响。通过LED变温电致发光测试系统对LED光电性能进行了表征。结果表明,100 K小电流时随着电流密度的增大,三组样品的绿光峰与黄光峰相对强度的比值越来越大,且5.5 A·cm^-2的电流密度下,随着温度从300 K逐步降低至100 K,三组样品的绿光峰与黄光峰相对强度的比值也越来越大,说明其载流子都在更靠近p型层的位置发生辐射复合。三组样品的p-GaN插入层厚度为0,10,30 nm时,EQE峰值依次为29.9%、29.2%和28.2%,呈现依次减小的趋势,归因于p-GaN插入层厚度越大,p型层越远离有源区,空穴注入也越浅。电子阻挡层前p-GaN插入层可以有效减小器件EL光谱中绿光峰随着电流密度增加时峰值波长的蓝移(33 nm),实现了对低温发光光谱的调控。     

Effect of Al doping on microstructure and optical band gap of ZnO thin film synthesized by successive ion layer adsorption and reaction

Thin films of pure and aluminum-doped zinc oxide (AZO) were deposited on glass substrates from ammonium zincate bath following a chemical dipping technique called successive ion layer adsorption and reaction (SILAR). Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-rays (EDX) were used to investigate the effect of Al doping on the microstructure of AZO films. Particle size analysis using X-ray line broadening shows marginally increasing trend with increasing Al impurity. The average particle size for pure ZnO is 22.75 nm. It increases to 24.26 nm for 1% AZO film and 25.13 nm for 2% AZO film. Incorporation of Al was confirmed from elemental analysis using EDX. SEM micrograph shows that pure ZnO particles are spherical shaped. However, AZO films show particles with off-spherical shape with compact interconnected grains. The value of band gap for pure ZnO is 3.229 eV and it increases to 3.29 eV for 1% AZO indicating a blue-shift for 1% AZO film. However, for 2% AZO film, a decrease in band gap compared to pure ZnO is observed indicating a red-shift of fundamental absorption edge. Electrical resistance shows an initial decrease with increasing Al content. With further enhancement of Al incorporation, the resistance increases.     

高温固相法制备ZnO∶Zn绿色荧光粉及其在近紫外LEDs中的应用研究

采用高温固相法在温度900～1 100 ℃,时间3 h的条件下制备出系列ZnO∶Zn荧光粉样品,并进行了封装应用研究。利用X射线衍射分析(XRD)、场发射扫描电子显微镜(FESEM)、荧光分光光度计(PL)和可见光光谱分析系统等手段对样品分别进行了表征分析。研究结果表明：所制备的荧光粉样品均具有ZnO晶型的六方纤锌矿结构,样品可以有效地被近紫外光激发,所发射的绿光光谱具有宽谱发射特征,峰位于502 nm归属于氧空位发射,同时940 ℃条件下制备的荧光粉样品具有最高的发光强度。结合近紫外LED芯片和RGB荧光粉分别制备出绿光LED和白光LED,其中绿光LED在不同驱动电流(250～500 mA)泵浦下表现出稳定的光谱发射特性,发射光谱谱型和色坐标基本未变,发射强度随电流升高而增加,所制备的白光LED在色温3 212 K时,显色指数达到94.1,发光效率为85.6 lm·W-1(@300 mA,9.3 V),在(250～500 mA)驱动电流泵浦下同时也表现出稳定的光谱发射特性,所制备的ZnO∶Zn绿色荧光粉对于制备高显色、高品质近紫外白光LED具有潜在的应用价值。     

Ultra‐thin (002)‐oriented Al‐doped zinc oxide transparent electrode grown on oxygen‐controlled homo‐seed layer

Highly (002)‐oriented Al‐doped zinc oxide (AZO) thin films with the thickness of less than 200 nm have been deposited on an oxygen‐controlled homo‐seed layer at 200 °C by DC magnetron sputtering. With the homo‐seed layer being employed, the full‐width at half maximum (FWHM) of the (002) diffraction peak for the AZO ultra‐thin films decreased from 0.33° to 0.22°, and, the corresponding average grain size increased from 26.8 nm to 43.0 nm. The XRD rocking curves revealed that the AZO ultra‐thin film grown on the seed layer deposited in atmosphere of O₂/Ar of 0.09 exhibited the most excellent structural order. The AZO ultra‐thin film with homo‐seed layer reached a resistivity of 4.2 × 10^–4 Ω cm, carrier concentration of 5.2 × 10²⁰ cm^–3 and mobility of 28.8 cm² V^–1 s^–1. The average transmittance of the AZO ultra‐thin film with homo‐seed layer reached 85.4% in the range of 380–780 nm including the substrate. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

有机薄膜电致发光器件的光学微腔效应

制备了以铝掺杂氧化锌（ＡＺＯ）透明导电膜为阳极的有机薄膜电致发光微腔器件，研究了垂直的光学法布里－珀罗微共振腔对有机器件的自发发射的微腔效应，发出了光谱窄化、发光强度增加及发射的角度依赖关系等现象。具有微腔结构的器件发射谱将高宽只有１４display status     

The investigation of ZnO：Al2O3/metal composite back reflectors in amorphous silicon germanium thin film solar cells

Different aluminum-doped ZnO （AZO）/metal composite thin films, including AZO/Ag/Al, AZO/Ag/nickelchromium alloy （NiCr）, and AZO/Ag/NiCr/Al, are utilized as the back reflectors of p-i-n amorphous silicon germanium thin film solar cells. NiCr is used as diffusion barrier layer between Ag and Al to prevent mutual diffusion, which increases the short circuit current density of solar cell. NiCr and NiCr/AI layers are used as protective layers of Ag layer against oxidation and sulfurization, the higher efficiency of solar cell is achieved. The experimental results show that the performance of a-SiGe solar cell with AZO/Ag/NiCr/Al back reflector is best. The initial conversion efficiency is achieved to be 8.05%.     

Performance improvement of InGaN blue light-emitting diodes with several kinds of electron-blocking layers

The performance of InGaN blue light-emitting diodes(LEDs) with different kinds of electron-blocking layers is investigated numerically.We compare the simulated emission spectra,electron and hole concentrations,energy band diagrams,electrostatic fields,and internal quantum efficiencies of the LEDs.The LED using AlGaN with gradually increasing Al content from 0% to 20% as the electron-blocking layer(EBL) has a strong spectrum intensity,mitigates efficiency droop,and possesses higher output power compared with the LEDs with the other three types of EBLs.These advantages could be because of the lower electron leakage current and more effective hole injection.The optical performance of the specifically designed LED is also improved in the case of large injection current.     

Low-threshold pure UV electroluminescence from n-ZnO:Al/i-layer/n-GaN heterojunction

Ultraviolet (UV) electroluminescence (EL) of n-ZnO:Al (AZO)/i-layer/n-GaN heterojunctions with different intrinsic layers has been obtained. Rectifying behavior and EL spectra of the heterojunctions are investigated at room temperature. Under positive voltage, a dominant UV emission peak around ～370 nm is observed for both AZO/i-ZnO/n-GaN and AZO/i-MgO/n-GaN heterojunctions. Nevertheless, the UV emission peak intensity of AZO/i-MgO/n-GaN heterojunction is much stronger than that of AZO/i-ZnO/n-GaN heterojunction at the same voltage. The threshold voltage of AZO/i-MgO/n-GaN heterostructured device is as low as 2.3 V. The difference of EL spectra and the emission mechanism in these devices are discussed.