Photore sponse and H2 gas sensing properti es of highly oriented Al and Al/Sb doped ZnO thin films

ZnO:Al and ZnO:Al/Sb thin films have been prepared and investigated.The thin films were deposited on Si substrates by the sol-gel method.The structural,optical and electrical properties of ZnO films have been investigated by spectrophotometry,ellipsometry,X-ray diffraction and current-voltage characterizations.It is found that the films exhibit wurtzite structure with a highly c-axis orientation perpendicular to the surface of the substrate,a high reflectivity in the infrared region and a response to illumination.Furthermore,it has been found that Si/（ZnO:Al/Sb）/Al photodiode is promising in photoconduction device while Si/（ZnO:Al）/Al can be used as gas sensor responding to the low H₂concentrations.     

Influence of O2/Ar ratio on the properties of transparent conductive niobium-doped ZnO films

Niobium-doped ZnO transparent conductive films are deposited on glass substrates by radio frequency sputtering at 300℃. The influence of O2/Ar ratio on the structural, electrical and optical properties of the as-deposited films is investigated by X-ray diffraction, Hall measurement and optical transmission spectroscopy. The lowest resistivity of 4.0×10^-4Ω· cm is obtained from the film deposited at the O2/Ar ratio of 1/12. The average optical transmittance of the films is over 90%.     

自持金刚石厚膜上沉积N掺杂ZnO薄膜的生长及电学特性

采用金属有机化合物气相沉积(MOCVD)两步生长法在自持化学气相沉积(CVD)金刚石厚膜的成核面上制备ZnO薄膜, 并研究了薄膜的生长特性和电学特性. 结果表明, 在基片温度为600 ℃时沉积得到的ZnO薄膜表面均匀, 取向较一致, 为c轴取向生长. 其载流子迁移率为3.79 cm²/(V·s).      

Effect of oxygen content on the structural and optical properties of ZnO films grown by atmospheric pressure MOCVD

Atmospheric pressure MOCVD was used to deposit ZnO layers on sapphire and homoepitaxial template under different oxygen flow rates.Oxygen content affects the lattice constant value and texture coefficient of the films as evidenced by the θ-2θ peaks position and their intensity.Films deposited at lower oxygen flow rate possess higher value of strain and stresses.ZnO films deposited at high oxygen flow rates show intense UV emissions while samples prepared under oxygen deficient conditions exhibited defect related emission along with UV luminescence.The results are compared to the ZnO films deposited homoepitaxially on annealed ZnO samples.The data obtained suggest that ZnO stoichiometry is responsible for the structural and optical quality of ZnO films.     

Effect of oxygen partial pressure and transparent substrates on the structural and optical properties of ZnO thin films and their performance in energy harvesters

Zinc oxide (ZnO) thin films were deposited onto different substrates-tin-doped indium oxide (ITO)/glass, ITO/polyethylene naphthalate (PEN), ITO/polyethylene terephthalate (PET)-by the radio-frequency (RF) magnetron sputtering method. The effect of various O₂/(Ar+O₂) gas flow ratios (0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6) was studied in detail. ZnO layers deposited onto ITO/PEN and ITO/PET substrates exhibited a stronger c-axis preferred orientation along the (0002) direction compared to ZnO deposited onto ITO/glass. The transmittance spectra of ZnO films showed that the maximum transmittances of ZnO films deposited onto ITO/glass, ITO/PEN, and ITO/PET substrates were 89.2%, 65.0%, and 77.8%, respectively. Scanning electron microscopy (SEM) images of the film surfaces indicated that the grain was uniform. The cross-sectional SEM images showed that the ZnO films were columnar structures whose c-axis was perpendicular to the film surface. The test results for a fabricated ZnO thin film based energy harvester showed that its output voltage increased with increasing acceleration of external vibration.     

衬底偏压对ZnO：Zr薄膜结构及光电性能的影响

以Zn：Zr（Zr片贴在金属Zn靶上面）为溅射靶材,利用直流反应磁控溅射法在Ar／O_2混合气氛中制备Zr掺杂ZnO（ZnO：Zr）薄膜．在制备ZnO：Zr薄膜时,衬底偏压在0～60V之间变化．研究结果表明,衬底偏压对薄膜的结构、光学及电学性能有很大影响．当衬底偏压从0增大到60V时,薄膜的平均光学透过率和平均折射率都单调增大,而薄膜的晶粒尺寸先增大后减小．ZnO：Zr薄膜电阻率的变化规律与晶粒尺寸相反．     

缓冲层对AZO薄膜的性能影响

采用射频磁控溅射法分别在ZnO缓冲层和Al2O3缓冲层上制备Al掺杂ZnO(AZO)薄膜,利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、紫外-可见分光光度计、霍尔测试仪等仪器对薄膜的光电特性进行表征.XRD分析结果表明,加入缓冲层的薄膜具有更好的c轴择优取向,薄膜的表面平整,结晶质量有所改善,薄膜在可见光范围内的平均透过率超过80%.引入ZnO缓冲层制备的AZO薄膜的最低电阻率为5.8×10-4 Ω·cm,导电性能得到明显提高.     

High quality p-type ZnO film growth by a simple method and its properties

P-type ZnO：N films have been grown successfully by chemical vapor deposition （CVD） using Zn4（OH）2（O2CCH3）6·2H2O as the solid source material and ZnNO3 as the doping source material. XPS, Hall-effect measurement and PL spectra were employed to analyze the structural, electrical and optical properties and study the influence of substrate temperature on the film. Results showed that with a lower substrate temperature, the film exhibited p-type conduction and its resistivity decreased when the substrete temperature increased. When the substrates temperature was 400℃, p-type ZnO films were obtained with carrier concentration of ＋5.127×10^17 cm^-3, resistivity of 0.04706 Ω· cm and Hall mobility of 259 cm^2/（V·s）; they still exhibited p-type conduction after a month. When the substrate temperature was too high, the film was transformed from p-type to n-type conduction.     

γ′-Fe4N薄膜的制备及其磁性

采用直流磁控溅射方法, 以Ar/N₂为放电气体（N₂/(Ar+N₂)=10％）, 在玻璃和NaCl(100)单晶片上分别沉积获得Fe-N薄膜样品. 利用X射线衍射(XRD)、 原子力显微镜(AFM)和超导量子干涉仪(SQUID)对样品的结构、 形貌和磁性能进行分析, 研究基片和基片温度等条件对薄膜的影响. 结果表明, 以NaCl单晶为基片获得单相γ′-Fe₄N薄膜, 与玻璃基片相比可降低其生成的基片温度并可扩大形成温度的范围, 且比饱和磁化强度略有增大.      

Study on ZnO:Al (ZAO) films by DC reaction magnetron sputtering

The high quality ZnO: A1 films were successfully produced by DC reaction magnetron sputtering technology. The Al-doping effect on electrical and optical properties and its scattering mechanism are discussed in detail. The analyses of X-ray diffractometer (XRD), X-ray photoelectron spectroscopy(XPS) and high resolution Auger electron spectroscopy (AES) show that Al2O3 could be effectively removed by controlling oxygen flow and Al-doping concentration during deposition of ZnO: Al films. Zn, Al and oxygen elements are well distributed through the films. For highly degenerated ZnO:A1 semi-conductive thin films, the theoretical and experimental results reveal that the ionized impurity. scattering dominates the Hall mobility in the films in the low-temperature range, while the lattice vibration scattering becomes a major scattering mechanism in the high-temperature range. The grain boundary scattering only plays a major role in the ZAO films with small grain size (as compared to the electron mean free path). The photoelectric properties of ZAO films show that it has low resistivity ( ～ 5 × 10-4 Ωcm), and the transmittance in visible range and the reflectance in IR region are above 80% and 60%, respectively.     

Sb掺杂ZnO薄膜的缺陷和光学性质研究

采用磁控溅射方法在6H-SiC单晶片上制备了锑(Sb)掺杂的氧化锌(ZnO)薄膜.利用X射线衍射(XRD)和X射线光电子能谱(XPS)对样品的结晶质量和成分进行了测试.结果表明所得到的ZnO∶Sb薄膜结晶质量良好,掺Sb浓度为原子数分数1%,并且掺入的Sb原子处于Zn原子的位置.利用低温及变温光致发光谱(PL)研究了ZnO∶Sb薄膜的光学性质,观察到了与Sb有关的A0X发射,并且计算得到其受主能级为150meV.分析认为掺Sb的ZnO薄膜中受主来源于SbZn-2VZn复合缺陷.     

衬底温度和溅射功率对AZO薄膜性能的影响

采用RF磁控溅射法在载玻片上制备了可用于电极材料的掺Al氧化锌(AZO)透明导电薄膜,并对不同衬底温度和溅射功率下制备的AZO薄膜结构、光电性能进行了表征分析.结果表明:各种工艺条件下沉积的AZO薄膜均具有明显的(002)择优取向,没有改变ZnO六方纤锌矿结构;薄膜电阻率随衬底温度升高而减小,随溅射功率增加先减小后增大,衬底温度400℃、溅射功率200W时最小,为1.53×10-5Ω.m;可见光平均透射率均在80%以上,光学带隙与载流子浓度变化趋势一致,最大值为3.52eV.     

生长条件对TiO_2薄膜结构及光学性能的影响

为了研究TiO2薄膜的生长机制及结构对其带隙的影响,采用激光脉冲沉积方法在超高真空下制备了TiO2薄膜.X射线衍射结果显示在不同温度和不同缓冲层上生长的TiO2薄膜以板钛矿结构为主,缓冲层对薄膜结构影响不大,高的生长温度提高了薄膜的结晶度.透射谱的结果表明,随着生长温度和生长气压的升高,TiO2的带隙逐渐增大,在生长ZnO做为缓冲层后,TiO2薄膜的结晶度降低,随ZnO结晶度的提高,TiO2对复合薄膜带隙的影响消失.     

Electrodeposition and characterization of thermoelectric Bi<Subscript>2</Subscript>Se<Subscript>3</Subscript> thin films

Bi₂Se₃ thin films were electrochemically deposited on Ti and indium tin oxide-coated glass substrates, respectively, at room temperature, using Bi(NO₃)₃·5H₂O and SeO₂ as starting materials in diluted HNO₃ solution. A conventional three-electrode cell was used with a platinum sheet as a counter electrode, and a saturated calomel electrode was used as a reference electrode. The films were annealed in argon atmosphere. The influence of cold isostatic pressing before annealing on the microstructure and thermoelectric properties of the films was investigated. X-ray diffraction analysis indicates that the film grown on the indium tin oxide-coated glass substrate is pure rhombohedral Bi₂Se₃, and the film grown on the Ti substrate consists of both rhombohedral and orthorhombic Bi₂Se₃.     

铝掺杂氧化锌薄膜的光学性能及其微结构研究

以氧化铝(Al2O3)掺杂的氧化锌(Zn O)陶瓷靶作为溅射靶材,采用射频磁控溅射工艺在玻璃基片上制备了具有c轴择优取向的铝掺杂氧化锌(Zn O:Al)薄膜样品.通过可见-紫外光分光光度计和X射线衍射仪的测试表征,研究了生长温度对薄膜光学性能及其微结构的影响.实验结果表明:薄膜性能和微观结构与生长温度密切相关.随着生长温度的升高,样品的可见光平均透过率、(002)择优取向程度和晶粒尺寸均呈非单调变化,生长温度为640 K的样品具有最好的透光性能和晶体质量.同时薄膜样品的折射率均表现为正常色散特性,其光学能隙随生长温度升高而单调增大.与未掺杂Zn O块材的能隙相比,所有Zn O:Al薄膜样品的直接光学能隙均变宽.     

Correlation between structure and hardness of magnetron sputtering deposited CNx films

Carbon nitride films are deposited on Si (001) substrates by reactive dc magnetron sputtering graphite in a pure N2 discharge. The structure of carbon nitride films has been probed using Fourier transformation infrared, near edge X-ray absorption fine structure (NEXAFS) and high resolution electron microscopy (HREM), and the hardness has been evaluated in nanoin-dentation experiments. FTIR spectra show that N atoms are bound to sp1, sp2, and sp3 hybridized C atoms. C1s NEXAFS spectra show that the intensity of π* resonance is the lowest for the film grown at substrate temperature TS = 350℃, with a turbostratic-like structure and high hardness, while it is the highest for the film grown at TS = 100℃, with an amorphous structure and low hardness. The correlation between the structure and hardness of carbon nitride films has been discussed.     

Nd掺杂对ZnO薄膜结构及室温光致发光特性的影响

通过射频磁控溅射技术在Si（111）衬底上制备了不同含量的Nd掺杂ZnO薄膜.XRD和AFM分析表明,Nd掺杂没有改变ZnO薄膜的结构,薄膜为纳米多晶结构,未掺杂ZnO沿c择优生长.Nd掺杂使ZnO薄膜表面粗糙,起伏较大,薄膜中随Nd掺杂量的增加颗粒减小.室温光致发光谱显示,薄膜出现了395nm的强紫光峰和495nm的弱绿光峰,同时,Nd掺杂不改变PL谱的峰位置,Nd含量对PL谱的峰强度产生了一定影响.     

溅射气压对射频磁控溅射制备ZnO薄膜结构的影响

采用射频磁控溅射技术在玻璃衬底上制备ZnO薄膜.利用X射线衍射仪、原子力显微镜,分析了ZnO薄膜的晶体结构和表面形貌.结果表明:所制备的 ZnO薄膜是具有(002)晶面择优生长的多晶薄膜.溅射气压为0.3Pa时,薄膜的晶粒尺寸较大,结晶度提高.     

溅射沉积纳米ZnO膜的表征及其性能

利用RF磁控溅射法在PET非织造布表面沉积氧化锌（ZnO）薄膜,并利用原子力显微镜（AFM）和能量弥散X-射线法（EDX）对ZnO薄膜的表面形貌和结构进行表征和分析.结果表明,沉积的ZnO颗粒具备纳米级尺度,且颗粒分布均匀、膜层致密,薄膜颗粒中只含有Zn和O两种元素;随着沉积时间的延长,ZnO呈多层生长模式.测试表明,经ZnO镀层处理的PET非织造布具有较强的紫外线屏蔽效果和优良的抗静电效果.     

衬底温度对ZnO：Al薄膜结构和光透过性能的影响

利用超声喷雾热解方法以不同的沉积温度（450～530℃）在石英衬底上制备出具备较高光学质量的ZnO：Al（AZO）薄膜.通过X射线衍射谱（XRD）研究了薄膜的结构,用扫描电子显微镜（SEM）研究了薄膜的表面形貌,用紫外可见（UV）分光光度计对薄膜的光透过特性进行了测试分析.结果表明：所制备薄膜在可见波段具有较高透过率,并且沉积温度对AZO薄膜的结构和光透过性能有很大影响.在衬底温度为470℃时得到的AZO薄膜具有（002）择优取向,结晶质量最好、光透过率最高,在可见光区平均透过率达到85%以上.