磁控溅射制备ZnO薄膜的受激发射特性的研究

用射频磁控反应溅射法在二氧化硅衬底上制备ZnO薄膜。得到了在不同温度下ZnO薄膜的吸收与光致发光。观测到了纵光学波 (LO)声子吸收峰与自由激子吸收峰 ;室温 (30 0K)下 ,PL谱中仅有自由激子发光峰。这些结果证实了ZnO薄膜具有较高的质量。探讨了变温ZnO薄膜的发光特性。研究了ZnO薄膜的受激发射特性。     

射频磁控溅射法制备ZnO薄膜的发光特性

利用射频磁控溅射法在硅衬底上制备出具有（002）择优取向的氧化锌薄膜，用波长为300nm的光激发，观察到在446nm处有一强的光致发光峰，它来自于氧空位浅施主能级上的电子到价带上的跃迁。并讨论了发光峰与氧压的关系以及退火对它的影响，且给出了解释。     

射频磁控溅射法制备ZnO薄膜的绿光发射

用射频磁控溅射法,在硅衬底上制备出具有良好的(002)择优取向的多晶ZnO薄膜。研究了室温下薄膜的光致发光特性,观察到显著的单绿光发射(波长为514nm)峰。在氧气中830℃高温退火后,薄膜结晶质量明显提高,绿光发射峰强度变弱;在真空中830℃高温退火后,绿光发射峰强度增加。绿光发射源于氧空位深施主能级到价带顶的电子跃近。     

ZnO薄膜受激发射特性的研究

氧化锌薄膜因其大的激子结合能和强的光发射、激光阈值低和能在高温下工作等优点而成为制备短波长激光、发光二极管等光电子器件的有希望材料。采用激光分子束外延 (L MBE)方法制备了ZnO薄膜。在室温下 ,测量了样品的吸收光谱 ,以及不同光泵浦强度下的发射光谱。从光谱图中可以看出该材料有很好的质量。研究了ZnO薄膜的受激发射特性及机理 ;测量了发射光强与泵浦光强之间的关系 ;比较了较高激发密度下的受激发射、自发发射和激光脉冲的时间特性 ,这些都证实了该发射是受激发射。     

射频磁控溅射ZnO薄膜的结构和光学特性

采用射频（RF）反应磁控溅射法在n-Si(001)衬底上外延生长ZnO薄膜。XRD谱测量显示出较强的（002）衍射峰，表明ZnO薄膜为c轴择优取向生长的。室温PL谱测量观察到了较强的紫外光发射和深能级发射。     

磁控溅射制备ZnO薄膜及其声表面波特性

通过射频磁控溅射技术在GaAs，Au/GaAs，Si和玻璃基片上成功制备了ZnO多晶薄膜，利用X射线衍射对ZnO薄膜的取向、结晶性进行了表征，结果表明ZnO薄膜呈完全c轴取向，Au缓冲层可以有效地改善ZnO薄膜的晶体质量，X射线摇摆曲线结果表明ZnO(002)衍射峰的半高宽仅为2.41°，同时发现Au缓冲层的结晶质量对ZnO薄膜的c轴取向度有很大影响，通过扫描电子显微镜对ZnO/GaAs和ZnO/Au/GaAs薄膜的表面形貌进行了观测，利用网络分析仪对IDT/ZnO/GaAs薄膜的声表面波特性进行了测量. 关键词： ZnO薄膜 X射线衍射 声表面波     

磁控溅射制备ZnO薄膜的结构及发光特性研究

采用射频反应磁控溅射法在玻璃衬底上制备出具有c轴高择优取向的ZnO薄膜,利用X射线衍射、扫描探针显微镜及荧光分光光度法研究了生长温度对ZnO薄膜微观结构及光致发光特性的影响。结果表明,合适的衬底温度有利于提高ZnO薄膜的结晶质量;在室温下测量样品的光致发光谱(PL),观察到波长位于400 nm左右的紫光、446 nm左右的蓝色发光峰及502 nm左右微弱的绿光峰,随衬底温度升高,样品的PL谱中紫光及蓝光强度逐渐增大,同时,绿光峰的强度也表现出一定程度的增强。经分析得出紫光应是激子发光所致,而锌填隙则是引起蓝光发射的主要原因,502 nm左右的绿光峰应该是氧的深能级缺陷造成的。此外,还测量了样品的吸收谱,并结合样品吸收谱的拟合结果对光致发光机理的分析作了进一步的验证。     

高质量纳米ZnO薄膜的光致发光特性研究

报道了利用低压-金属有机物化学气相沉积技术生长纳米ZnS薄膜，然后，将ZnS薄膜在氧气中于800℃温度下进行热氧化制备高质量纳米ZnO薄膜.x射线衍射结果表明，纳米ZnO薄膜具有六角纤锌矿多晶结构.室温下观察到一束强的紫外(3.26 eV) 光致发光和很弱的深能级发射.根据激子峰的半高宽度与温度的关系确定了激子-纵向光学声子（LO）的耦合强度（ГLO）.由于量子限域效应使ГLO减少较多. 关键词： 光致发光 热氧化 激子 纳米ZnO薄膜     

射频磁控溅射沉积的ZnO薄膜的光致发光中心与漂移

利用射频磁控溅射法在n型单晶硅衬底上制备了ZnO薄膜.通过改变源气体中氩气和氧气的流量比制备了具有不同化学计量比的ZnO薄膜，并且将它们在真空中作了加热后处理来研究ZnO薄膜的光致发光特性.这些在常温衬底上沉积的薄膜可发出强的蓝光，其峰位会随氧流量的减少而发生红移.从导带底到锌缺陷形成的受主能级之间的跃迁可能是产生蓝光发射的原因. 关键词： ZnO薄膜 光致发光 退火 蓝光发射     

ZnO薄膜的制备和发光特性的研究

用射频磁控溅射的方法在石英衬底上沉积了氧化锌薄膜，在室温下测量了样品的XRD曲线、吸收光谱以及光致发光光谱。探讨了气氛中氧气与氩气比对制备薄膜的影响，从XRD谱中可以看出，样品具有较好的结晶状态。另外，样品在紫外有较强的吸收，而其光致发光也是较强的紫外发射，这表明带间跃迁占了主导地位，以上结果说明：用溅射方法制备的ZnO薄膜结晶质量较好，富锌状态有所改善。     

衬底温度对反应磁控溅射W掺杂ZnO薄膜的微观结构及光电性能的影响

采用直流脉冲反应磁控溅射方法生长W掺杂ZnO（WZO）透明导电氧化物薄膜并研究了衬底温度对薄膜微观结构、组分、表面形貌以及光电性能的影响.实验结果表明,WZO薄膜具有良好的（002）晶面择优取向,且适当的衬底温度是制备优质WZO薄膜的关键因素.随着衬底温度升高,薄膜表面粗糙度先增大后减小;衬底温度较高时,薄膜的结构致密,结晶质量好,电子迁移率高.当衬底温度为325℃时,WZO薄膜获得最低电阻率9.25×10^-3Ω·cm,方块电阻为56.24Ω/□,迁移率为11.8 cm² V^-1·s^-1,其在可见光及近红外区域（400—1500 nm）范围的平均透过率达到85.7%.     

Characterization of ZnO thin film synthesized on alumina-rich spinel substrate by magnetron sputtering

Zinc oxide (ZnO) thin film has been epitaxially grown on (1 1 1) Mg_0.4Al_2.4O₄ substrate by RF-magnetron sputtering. In resonant Raman scattering, higher-order longitudinal optical phonon modes were clearly observed, revealing high optical quality of the ZnO film. Optical absorption indicated a visible exciton absorption at room temperature. The near band edge emission showed a red shift due to the shrinkage of the band gap with increasing the temperature.     

Ferromagnetism in Eu-doped ZnO films deposited by radio-frequency magnetic sputtering

This paper reports that Eu-doped ZnO films were successfully deposited on silicon (100) by radio-frequency magnetic sputtering. The x-ray diffraction patterns indicate that Eu substitutes for Zn in the lattice. Ferromagnetic loops were obtained by using superconducting quantum interference device at 10 K and room temperature. No discontinuous change was found in both of the zero-field-cooled and field-cooled curves. The observed ferromagnetism in Eu-doped ZnO can be attributed to a single magnetic phase. The saturation magnetisation decreased remarkably for the Eu-doped ZnO prepared by introducing 5% of oxygen in the sputtering gas or by the post annealing in O2, suggesting that the defects play key roles in the development of ferromagnetism in Eu-doped ZnO films.     

Characteristics of ZnO:In thin films prepared by RF magnetron sputtering

In-doped ZnO (ZnO:In) transparent conductive thin films were deposited on glass substrates by RF magnetron sputtering. The effect of substrate temperature on the structural, electrical and optical properties of the ZnO:In thin films was investigated. It was found that higher temperature improves the crystallinity of the films and promotes In substitution easily. ZnO:In thin films with the best crystal quality were fabricated at 300 °C, which exhibit a larger grain size of 29 nm and small tensile strain of 0.9%. The transmittance of all the films was revealed to be over 85% in the visible range independence of the substrate temperatures and the lowest resistivity of ZnO:In thin films is 2.4×10⁻³ Ω cm.     

Induced growth of high quality ZnO thin filmsby crystallized amorphous ZnO

This paper reports the induced growth of high quality ZnO thin film by crystallized amorphous ZnO. Firstly amorphous ZnO was prepared by solid-state pyrolytic reaction, then by taking crystallized amorphous ZnO as seeds (buffer layer), ZnO thin films have been grown in diethyene glycol solution of zinc acetate at 80℃. X-ray Diffraction curve indicates that the films were preferentially oriented [001] out-of-plane direction of the ZnO. Atomic force microscopy and scanning electron microscopy were used to evaluate the surface morphology of the ZnO thin film. Photoluminescence spectrum exhibits a strong ultraviolet emission while the visible emission is very weak. The results indicate that high quality ZnO thin film was obtained.     

Effect of annealing on the properties of N-doped ZnO films deposited by RF magnetron sputtering

N-doped ZnO films were deposited by RF magnetron sputtering in N₂/Ar gas mixture and were post-annealed at different temperatures (T_a) ranging from 400 to 800 °C in O₂ gas at atmospheric pressure. The as-deposited and post-annealed films were characterized by their structural (XRD), compositional (SIMS, XPS), optical (UV-vis-NIR spectrometry), electrical (Hall measurements), and optoelectronic properties (PL spectra). The XRD results authenticate the improvement of crystallinity following post-annealing. The weak intensity of the (0 0 2) reflection obtained for the as-deposited N-doped ZnO films was increased with the increasing T_a to become the preferred orientation at higher T_a (800 °C). The amount of N-concentration and the chemical states of N element in ZnO films were changed with the T_a, especially above 400 °C. The average visible transmittance (400-800 nm) of the as-deposited films (26%) was increased with the increasing T_a to reach a maximum of 75% at 600 °C but then decreased. In the PL spectra, A⁰X emission at 3.321 eV was observed for T_a = 400 °C besides the main D⁰X emission. The intensity of the A⁰X emission was decreased with the increasing T_a whereas D⁰X emission became sharper and more optical emission centers were observed when T_a is increased above 400 °C.     

Effects of sapphire substrates surface treatment on the ZnO thin films grown by magnetron sputtering

The surface treatment effects of sapphire substrate on the ZnO thin films grown by magnetron sputtering were studied. The sapphire substrates properties have been investigated by means of atomic force microscopy (AFM) and X-ray diffraction rocking curves (XRCs). The results show that sapphire substrate surfaces have the best quality by CMP with subsequent chemical etching. The surface treatment effects of sapphire substrate on the ZnO thin films were examined by X-ray diffraction (XRD) and photoluminescence (PL) measurements. Results show that the intensity of (0 0 2) diffraction peak of ZnO thin films on sapphire substrates treated by CMP with subsequent chemical etching was strongest, FWHM of (0 0 2) diffraction peak is the narrowest and the intensity of UV peak of PL spectrum is strongest, indicating surface treatment on sapphire substrate preparation may improve ZnO thin films crystal quality and photoluminescent property.     

Field emission property of copper nitride thin film deposited by reactive magnetron sputtering

Copper nitride (Cu₃N) thin film was deposited on silicon (Si) substrate by reactive magnetron sputtering method. X-ray diffraction measurement showed that the film was composed of Cu₃N crystallites with anti-ReO₃ structure and exhibited preferential orientation of [1 0 0] direction. The field emission (FE) result showed that Cu₃N film had a turn-on electric field of about 3 V/μm at a current density of 1 μA/cm² and a current density of 700 μA/cm² was obtained at the electric field of 24 V/μm. The emission mechanism inferred by Fowler-Nordheim (FN) plot is shown as following: thermal electron emission at low field region and tunneling electron emission at high field region.     

Effects of post-annealing on the structural and nanomechanical properties of Ga-doped ZnO thin films deposited on glass substrate by rf-magnetron sputtering

In this study, the effects of post-annealing on the structure, surface morphology and nanomechanical properties of ZnO thin films doped with a nominal concentration of 3 at.% Ga (ZnO:Ga) are investigated using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) and nanoindentation techniques. The ZnO:Ga thin films were deposited on the glass substrates at room temperature by radio frequency magnetron sputtering. Results revealed that the as-deposited ZnO:Ga thin films were polycrystalline albeit the low deposition temperature. Post-annealing carried out at 300, 400 and 500 °C, respectively, has resulted in progressive increase in both the average grain size and the surface roughness of the ZnO:Ga thin film, in addition to the improved thin films crystallinity. Moreover, the hardness and Young's modulus of ZnO:Ga thin films are measured by a Berkovich nanoindenter operated with the continuous contact stiffness measurements (CSM) option. The hardness and Young's modulus of ZnO:Ga thin films increased as the annealing temperature increased from 300 to 500 °C, with the best results being obtained at 500 °C.