退火温度对ZnO薄膜结构和发光特性的影响

采用反应射频磁控溅射法在 Si(100)基片上制备了高c轴择优取向的ZnO薄膜，研究了退火温度对ZnO薄膜的晶粒尺度、应力状态、成分和发光光谱的影响，探讨了ZnO薄膜的紫外发光光谱和可见发光光谱与薄膜的微观状态之间的关系.研究结果显示,在600—1000℃退火温度范围内，退火对薄膜的织构取向的影响较小，但薄膜的应力状态和成分有比较明显的变化.室温下光致发光光谱分析发现，薄膜的近紫外光谱特征与薄膜的晶粒尺度和缺陷状态之间存在着明显的对应关系；而近紫外光谱随退火温度升高所呈现的整体峰位红移是各激子峰相对比例变 关键词： ZnO薄膜 退火 光致发光 射频反应磁控溅射 可见光发射     

L-MBE法生长ZnO薄膜的退火研究

研究了空气退火对于激光分子束外延(L-MBE)法制备的ZnO薄膜光学及结构特性的影响,报道了采用小角度X射线分析(GIXA)技术对于ZnO薄膜退火前后的表面及界面状况的定量分析结果.RHEED衍射图样表明,薄膜经过380℃及600℃原位退火后,其表面仍然较为粗糙.而XRD在面(in-plane)Φ扫描结果显示出经过800℃空气退火之后,薄膜具有更好的外延取向性.GIXA分析结果表明,800℃退火后ZnO薄膜的表面方均根粗糙度从退火前的1.13 nm下降为0.37 nm;同时ZnO/Al2O3界面粗糙度从2.10 nm上升为2.59 nm.ZnO室温PL结果显示,退火后薄膜紫外近带边发光强度比退火前增大了40倍,并出现了源于电子－空穴等离子体(EHP)复合的N带受激发射峰,激发阈值约为200 kW/cm2.     

退火对ZnO薄膜光学特性的影响

用射频磁控溅射法在蓝宝石衬底上制备出ZnO薄膜,通过X射线衍射(XRD)、扫描电镜(SEM)和光致发光(PL)谱等研究了退火温度对ZnO薄膜结构和光学性质的影响。测量结果显示,所制备的ZnO薄膜为六角纤锌矿结构,具有沿c轴的择优取向;随着退火温度的升高,(002)XRD峰强度和平均晶粒尺寸增大,(002)XRD峰半高宽(FWHM)减小,光致发光紫外峰强度增强。结果证明,用射频磁控溅射法通过适当控制退火温度可得到高质量ZnO薄膜。     

退火对常压MOCVD法生长的高结晶性能 ZnO薄膜发光特性的影响

研究了氧气退火和氮气退火对ZnO薄膜发光特性的影响。ZnO膜是采用常压金属有机化学气相沉积（MOCVD）法在蓝宝石（0001）衬底上生长的。原生样品1有一很强的紫外峰及较强的绿光峰（525nm附近）;原生样品2有很强的紫外峰,深能级发光几乎观察不到。然后从不同原生膜上取两块小样品,分别在氧气和氮气中退火,退火温度是400,500,600,700,800℃。结果表明,在700℃以下退火,退火气氛对ZnO膜的深能级发光影响较大;超过700℃后,退火温度对ZnO薄膜的发光影响大,但退火气氛影响不太明显。通过退火对ZnO薄膜发光特性的影响,讨论了ZnO膜中525nm附近绿光峰的起源。     

Al/ZnO/Al薄膜的结构与磁性分析

采用直流磁控溅射的方法制备了Al/ZnO/Al纳米薄膜,并对薄膜分别在真空及空气中进行退火处理.利用X射线衍射仪(XRD)和物理性能测量仪(PPMS)分别对薄膜样品的结构和磁性进行了表征.XRD分析表明,不同的退火氛围对薄膜的微结构有着很大的影响.采用了一种新的修正方法对磁测量结果进行修正,计算了基底拟合误差的最大值,并对修正后样品的磁性进行了分析.结果显示,室温铁磁性可能与Al和ZnO基体之间发生的电荷转移以及在不同退火氛围下Al在ZnO晶格中的地位变化有关. 关键词： Al/ZnO/Al薄膜 铁磁性 磁性表征     

退火温度对Cr掺杂ZnO薄膜的微结构与机械性能的影响研究

本研究利用射频磁控溅镀法在玻璃基板上制备3 at.%的Cr掺杂ZnO薄膜,再以300℃～500℃温度退火处理25 mins,并探讨了退火温度对Al掺杂ZnO薄膜的微观结构与机械性能的影响.微观结构分析结果表明Cr掺杂ZnO薄膜的结晶方向为(002),且沿(002)方向的成长随退火温度升高而越加明显,但薄膜的表面却随退火温度升高而变得越来越粗糙.机械性能分析结果揭示晶粒尺寸随退火温度升高而增大,导致差排原子的动能随之降低,致使Cr掺杂ZnO薄膜的硬度随退火温度升高而增大,但对其对杨氏模量却没有太大的影响;此外,Cr掺杂ZnO薄膜的耐磨性与韧性均随退火温度升高而增强,表明退火处理对该薄膜的抗塑性形变能力有很大帮助.     

退火温度对Cr掺杂ZnO薄膜的微结构与机械性能的影响研究

本研究利用射频磁控溅镀法在玻璃基板上制备3 at.%的Cr掺杂ZnO薄膜,再以300℃～500℃温度退火处理25 mins,并探讨了退火温度对Al掺杂ZnO薄膜的微观结构与机械性能的影响.微观结构分析结果表明Cr掺杂ZnO薄膜的结晶方向为(002),且沿(002)方向的成长随退火温度升高而越加明显,但薄膜的表面却随退火温度升高而变得越来越粗糙.机械性能分析结果揭示晶粒尺寸随退火温度升高而增大,导致差排原子的动能随之降低,致使Cr掺杂ZnO薄膜的硬度随退火温度升高而增大,但对其对杨氏模量却没有太大的影响;此外,Cr掺杂ZnO薄膜的耐磨性与韧性均随退火温度升高而增强,表明退火处理对该薄膜的抗塑性形变能力有很大帮助.     

退火温度对Cr掺杂ZnO薄膜的微结构与机械性能的影响研究

本研究利用射频磁控溅镀法在玻璃基板上制备3 at.%的Cr掺杂ZnO薄膜,再以300℃～500℃温度退火处理25 mins,并探讨了退火温度对Al掺杂ZnO薄膜的微观结构与机械性能的影响.微观结构分析结果表明Cr掺杂ZnO薄膜的结晶方向为(002),且沿(002)方向的成长随退火温度升高而越加明显,但薄膜的表面却随退火温度升高而变得越来越粗糙.机械性能分析结果揭示晶粒尺寸随退火温度升高而增大,导致差排原子的动能随之降低,致使Cr掺杂ZnO薄膜的硬度随退火温度升高而增大,但对其对杨氏模量却没有太大的影响;此外,Cr掺杂ZnO薄膜的耐磨性与韧性均随退火温度升高而增强,表明退火处理对该薄膜的抗塑性形变能力有很大帮助.     

热处理对ZnO/Au薄膜结构和压电特性的影响

通过射频磁控溅射在氧化硅片表面沉积ZnO/Au薄膜,并通过不同的热处理方式对薄膜进行退火。为了研究退火对ZnO/Au薄膜结构和压电特性的影响,采用X射线衍射分析（XRD）、光学显微镜、场发射扫面电镜（FESEM）和压电力分析仪对薄膜退火前后的材料特性进行了分析。研究发现,热处理能够改善ZnO/Au薄膜的结晶质量。特别是在氮气保护氛围下慢速退火后,薄膜结晶质量有明显改善。但是,热处理导致了薄膜的压电系数d33和d31降低。分析认为,热处理过程中Au原子在ZnO中的易迁移特性破坏了ZnO/Au薄膜的压电性能。     

热处理对ZnO/Au薄膜结构和压电特性的影响（英文）

通过射频磁控溅射在氧化硅片表面沉积ZnO/Au薄膜,并通过不同的热处理方式对薄膜进行退火。为了研究退火对ZnO/Au薄膜结构和压电特性的影响,采用X射线衍射分析(XRD)、光学显微镜、场发射扫面电镜(FESEM)和压电力分析仪对薄膜退火前后的材料特性进行了分析。研究发现,热处理能够改善ZnO/Au薄膜的结晶质量。特别是在氮气保护氛围下慢速退火后,薄膜结晶质量有明显改善。但是,热处理导致了薄膜的压电系数d33和d31降低。分析认为,热处理过程中Au原子在ZnO中的易迁移特性破坏了ZnO/Au薄膜的压电性能。     

Effects of high-dose Ge ion implantation and post-implantation annealing on ZnO thin films

This paper reports that ion implantation to a dose of 1×10¹⁷ ions/cm² was performed on c-axis-orientated ZnO thin films deposited on (0001) sapphire substrates by the sol-gel technique. After ion implantation, the as-implanted ZnO films were annealed in argon ambient at different temperatures from 600-900℃. The effects of ion implantation and post-implantation annealing on the structural and optical properties of the ZnO films were investigated by x-ray diffraction (XRD), photoluminescence (PL). It was found that the intensities of (002) peak and near band edge (NBE) exitonic ultraviolet emission increased with increasing annealing temperature from 600-900℃. The defect related deep level emission (DLE) firstly increased with increasing annealing temperature from 600- 750℃, and then decreased quickly with increasing annealing temperature. The recovery of the intensities of NBE and DLE occurs at \sim 850℃ and \sim 750℃ respectively. The relative PL intensity ratio of NBE to DLE showed that the quality of ZnO films increased continuously with increasing annealing temperature from 600 - 900℃.     

Effects of sapphire substrate annealing on ZnO epitaxial films grown by MOCVD

The annealing effects of sapphire substrate on the quality of epitaxial ZnO films grown by metalorganic chemical vapor deposition (MOCVD) were studied. The atomic steps formed on (0 0 0 1) sapphire (α-Al₂O₃) substrate surface by annealing at high temperature was analyzed by atomic force microscopy (AFM). The annealing effects of sapphire substrate on the ZnO films were examined by X-ray diffraction (XRD), AFM and photoluminescence (PL) measurements. Experimental results indicate that the film quality is strongly affected by annealing treatment of the sapphire substrate surface. The optimum annealing temperature of sapphire substrates is given.     

退火及超声处理对ZnO薄膜结构和发光特性的影响

 利用对向靶射频磁控溅射系统在Si（100）衬底上制备了ZnO薄膜，并对其进行了退火和超声处理。采用XRD,AFM和光致发光谱对其结构、表面形貌和性能进行了分析。结果表明：沉积态ZnO薄膜（002）择优取向稍差,尺寸较小,表面粗糙度较大。随退火温度的升高，颗粒粒径增大，样品的取向性和结晶度都明显变好，应力状态由压应力转变为张应力,粗糙度降低。超声处理缓解了薄膜中的张应力，晶粒尺寸更趋增大;用波长为280 nm的激发光激发薄膜时，沉积态薄膜无发光峰存在;随着退火温度升高，出现了一个378 nm的紫外峰和一个398 nm的紫峰;紫外峰峰值强度随退火温度升高不断增强，而紫峰的峰位随退火温度升高基本不发生变化，峰值强度增强;700 ℃退火后的薄膜经超声处理后，发光谱中出现了峰值波长为519 nm的绿色发光带。     

Optical properties of ZnO and ZnO:Ce layers grown by spray pyrolysis

In this paper, zinc oxide (ZnO) and cerium-doped zinc oxide (ZnO:Ce) films were deposited by reactive chemical pulverization spray pyrolysis technique using zinc and cerium chlorides as precursors. The effects of Ce concentration on the structural and optical properties of ZnO thin films were investigated in detail. These films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) measurements. All deposited ZnO layers at the temperature 450 °C are polycrystalline and indicate highly c-axis oriented structure. The dimension of crystallites depends on incorporation of Ce atoms into the ZnO films. The photoluminescence spectra of the films have been studied as a function of the deposition parameters such as doping concentrations and post grows annealing. Photoluminescence spectra were measured at the temperature range from 13 K to 320 K.     

Effect of different annealing temperature on Sb-doped ZnO thin films prepared by pulsed laser deposition on sapphire substrates

Influence of annealing temperature on the properties of Sb-doped ZnO thin films were studied. Hall measurement results indicated that the Sb-doped ZnO annealed at 950 °C was p-type conductivity. X-ray diffraction (XRD) results indicated that the Sb-doped ZnO thin films prepared at the experiments are high c-axis oriented. It was worth noting that p-type sample had the worst crystallinity. The measurements of low-temperature photoluminescence (PL) spectra indicate that the sample annealed at the temperatures of 950 °C showed strong acceptor-bound exciton (A⁰X) emission, and confirmed that it is related to Sb-doping by comparing with the undoped ZnO low-temperature PL spectrum.     

Rapid thermal annealing effects on the structural and optical properties of ZnO films deposited on Si substrates

The structural and optical properties of ZnO films deposited on Si substrate following rapid thermal annealing (RTA) have been investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), and photoluminescence (PL) measurements. After RTA treatment, the XRD spectra have shown an effective relaxation of the residual compressive stress, an increase of the intensity and narrowing of the full-width at half-maximum (FWHM) of the (0 0 2) diffraction peak of the as-grown ZnO film. AFM images show roughening of the film surface due to increase of grain size after RTA. The PL spectrum reveals a significant improvement in the UV luminescence of ZnO films following RTA at 800 °C for 1 min.     

Effect of annealing temperature and annealing atmosphere on the structure and optical properties of ZnO thin films on sapphire (0 0 0 1) substrates by magnetron sputtering

ZnO thin films were epitaxially grown on sapphire (0 0 0 1) substrates by radio frequency magnetron sputtering. ZnO thin films were then annealed at different temperatures in air and in various atmospheres at 800 °C, respectively. The effect of the annealing temperature and annealing atmosphere on the structure and optical properties of ZnO thin films are investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL). A strong (0 0 2) diffraction peak of all ZnO thin films shows a polycrystalline hexagonal wurtzite structure and high preferential c-axis orientation. XRD and AFM results reveal that the better structural quality, relatively smaller tensile stress, smooth, uniform of ZnO thin films were obtained when annealed at 800 °C in N₂. Room temperature PL spectrum can be divided into the UV emission and the Visible broad band emission. The UV emission can be attributed to the near band edge emission (NBE) and the Visible broad band emission can be ascribed to the deep level emissions (DLE). By analyzing our experimental results, we recommend that the deep-level emission correspond to oxygen vacancy (V_O) and interstitial oxygen (O_i). The biggest ratio of the PL intensity of UV emission to that of visible emission (I_NBE/I_DLE) is observed from ZnO thin films annealed at 800 °C in N₂. Therefore, we suggest that annealing temperature of 800 °C and annealing atmosphere of N₂ are the most suitable annealing conditions for obtaining high quality ZnO thin films with good luminescence performance.     

Microstructure and optical properties of ZnO/porous silicon nanocomposite films

In this study, porous silicon (PS) templates were formed by electrochemical anodization on p-type (100) silicon wafer and ZnO films were deposited on PS substrates using radio frequency (RF) reactive magnetron sputtering technique. The effects of oxygen partial pressures of growth ZnO films and annealing ambience on the microstructure and photoluminescence (PL) of the ZnO/PS nanocomposite films were systematically investigated by X-ray diffraction and fluorescence spectrophotometry. The results indicated that all ZnO/PS nanocomposite films were polycrystalline in nature with a hexagonal wurtzite structure and the (002) oriented ZnO films had the best crystal quality under O₂:Ar ratio of 10:10 sccm and annealing in vacuum. PL measurements at room temperature revealed that ZnO/PS nanocomposite systems formed a broad PL band including the blue and green emissions from ZnO and red-orange emission from the PS. The mechanism and interpretation of broadband PL of the nanocomposites were discussed in detail using an oxygen-bonding model in PS and a native defects model in ZnO.