磁控溅射氧化钛薄膜的电学特性研究

采用直流磁控溅射法在K9玻璃上制备了不同溅射温度和氧气流量的氧化钛(TiOx)薄膜.采用XPS、霍尔效应测试仪对薄膜的组份、载流子浓度和迁移率进行了测试,发现随着溅射氧气流量的增大,薄膜中的氧元素比例增大,载流子浓度减小,迁移率增大.分析了TiOx薄膜的电阻温度系数(TCR)与溅射温度和氧分压的关系,薄膜的电阻率从0....     

透明导电ZnO：Sn薄膜光学和电学性能的研究进展

纯ZnO电阻率高,电学性能不稳定,通过掺杂其他元素提高其光电性能,制备出高质量的ZnO薄膜是实现其应用的关键。文章从制备方法、掺杂浓度和退火等方面综述了Sn掺杂ZnO(ZnO:Sn)薄膜光电性能的研究进展,提出了降低ZnO:Sn薄膜电阻率和提高透光率的有效途径。     

In_2O_3∶Sn和ZnO∶Al透明导电薄膜的结构及其导电机制

基于对锡掺杂三氧化铟 ( Sn- doped In2 O3,简称 ITO)和铝掺杂氧化锌 ( Al- doped Zn O,简称 ZAO)薄膜退火前后 XRD数据的分析 ,研究了薄膜晶格常数畸变的原因 ,同时讨论了 ITO和ZAO薄膜的导电机制 .结果表明 ,低温沉积 ITO薄膜的晶格膨胀来源于 Sn2 +对 In3-的替换 ,导电电子则由氧缺位提供 ;高温在位制备和退火处理后薄膜的晶格收缩来源于 Sn4 + 对 In3+ 的替换 ,导电电子则主要由 Sn4 + 取代 In3+ 后提供 .低温 ZAO薄膜的晶格畸变来源于薄膜中的残余应力 ,导电电子的来源则同高温在位和退火处理后的薄膜一致 ,即由 Al3+ 对 Zn2 + 的替换和氧缺位两者     

In2O3：Sn和ZnO：Al透明导电薄膜的结构及其导电机制

基于对锡掺杂三氧化铟(Sn-doped In2O3,简称ITO)和铝掺杂氧化锌(Al-doped ZnO,简称ZAO)薄膜退火前后XRD数据的分析,研究了薄膜晶格常数畸变的原因,同时讨论了ITO和ZAO薄膜的导电机制.结果表明,低温沉积ITO薄膜的晶格膨胀来源于Sn2+对In3-的替换,导电电子则由氧缺位提供;高温在位制备和退火处理后薄膜的晶格收缩来源于Sn4+对In3+的替换,导电电子则主要由Sn4+取代In3+后提供.低温ZAO薄膜的晶格畸变来源于薄膜中的残余应力,导电电子的来源则同高温在位和退火处理后的薄膜一致,即由Al3+对Zn2+的替换和氧缺位两者共同提供     

本征和Al3+掺杂ZnO薄膜的特性研究

采用溶胶-凝胶方法在载玻片衬底上制备了本征及不同Al3+掺杂浓度的ZnO:Al薄膜,利用X射线衍射(XRD)、原子力显微镜,紫外-可见光吸收光谱及霍尔效应研究了Al3+掺杂浓度对ZnO:Al薄膜结构和光电性能的影响。结果显示,ZnO:Al薄膜为六角纤锌矿晶体结构,具有很高的沿c轴的(002)择优取向,Al3+掺杂并没有改变ZnO的晶体结构,只是Al取代了Zn;掺杂前后薄膜样品均在ZnO带边吸收的位置有较强的吸收而在可见光范围吸收较小;并且当Al3+掺杂浓度为1.5%(摩尔百分比)时所获得的ZnO:Al薄膜具有最小的电阻率,为26Ωcm。     

氩氧比对磁控溅射梯度AZO薄膜光电性能的影响

采用磁控溅射法在单晶硅和石英玻璃衬底上制备梯度铝掺杂的氧化锌(AZO)薄膜。利用X线衍射(XRD)、霍尔效应测试和紫外可见光分度计等研究了不同氩氧比(体积比)对梯度AZO薄膜结构和光电性能的影响。结果表明,氩氧比可以改善薄膜的结晶质量,且对电学性能的影响较大。随着氩氧比的增加,晶粒尺寸减小,结晶度稍有下降,薄膜的电阻率却显著降低,当氩氧比为1∶0时,薄膜具有最低的电阻率为6.85×10~(-4)Ω·cm。此外,所有的梯度AZO薄膜在可见光区的透过率均达到80%。     

电子束蒸发沉积TiN薄膜的电学特性研究

采用TCP(Transverse coupled plasma)等离子体辅助电子枪蒸镀技术,在玻璃衬底上制备了TiN薄膜。用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)研究了不同工艺条件对薄膜晶体结构和表面形貌的影响;用四探针法测量薄膜的电阻率变化。结果表明,所制备的TiN薄膜在(111)晶面有择优取向。与金属薄膜类似,TiN薄膜的平均表面粗糙度与电阻率之间存在近似线性关系,并且电阻率随残余应力增大而增大。     

ZnO-SnO_2透明导电膜的低温制备及性质

在室温下,采用射频磁控溅射法在70 5 9玻璃衬底上制备出Zn O- Sn O2 透明导电薄膜.制备的薄膜为非晶结构,并且薄膜的电阻率强烈地依赖于溅射气体中的氧分压.薄膜的最小电阻率为7.2 7×10 - 3Ω·cm,载流子浓度为4 .3e1 9cm- 3、霍尔迁移率为2 0 .5 cm2 / (V·s) ,在可见光范围内的平均透过率达到了90 % .     

制备工艺对ITO薄膜的电阻率及沉积速率的影响

采用射频磁控溅射法制备了氧化铟锡[ITO,In2O3:SnO2=90:10(质量比)]薄膜,详细探讨了溅射气氛氧氩体积比、溅射功率及溅射气压对ITO薄膜电阻率和沉积速率的影响。结果表明:溅射工艺参数对ITO薄膜电阻率和沉积速率的影响十分明显。随着氧氩体积比的增大,样品的电阻率显著增大,沉积速率下降;随着溅射功率的增加,ITO薄膜的电阻率先减小后略微增大,沉积速率上升;随着溅射气压升高,ITO薄膜的电阻率先减小后增大,当溅射气压增大到较大值时,ITO薄膜的电阻率又开始减小,而沉积速率则先上升后下降。     

沉积温度及热处理对AZO纳米叠层薄膜性能的影响

采用原子层沉积技术(ALD)在石英片和n型(100)Si上沉积高阻氧化锌铝(AZO)纳米叠层薄膜,通过扫描电镜(SEM)、原子力显微镜(AFM)和X射线衍射仪(XRD)和体积表面电阻率测试仪对薄膜的表面形貌、晶体结构及电学性能进行表征分析,分别研究了不同沉积温度及退火温度对薄膜结构及性质的影响。研究结果表明AZO薄膜存在最优的生长温度窗口为170～200℃,同时发现,经过退火处理的薄膜电阻率明显增大,且适当的退火有助于薄膜结构的优化,经过400℃下退火4 h后的薄膜电阻趋于稳定,可作为微通道板(MCP)打拿极高阻导电层材料。     

Pulsed laser deposition of ITO thin films and their characteristics

The indium tin oxide (ITO) thin films are grown on quartz glass substrates by the pulsed laser deposition method. The structural, electrical, and optical properties of ITO films are studied as a function of the substrate temperature, the oxygen pressure in the vacuum chamber, and the Sn concentration in the target. The transmittance of grown ITO films in the visible spectral region exceeds 85%. The minimum value of resistivity 1.79 × 10⁻⁴ Ω cm has been achieved in the ITO films with content of Sn 5 at %.     

Epitaxial (La,Sr)TiO3 as a conductive buffer for high temperature superconducting coated conductors

The transport and structural properties of (La,Sr)TiO₃ epitaxial thin films grown by pulsed-laser deposition is presented. In particular, the potential use of (La,Sr)TiO₃ as a conductive buffer layer for subsequent growth of high temperature superconducting films for coated conductors is discussed. Van der Pauw measurements of film resistivity as a function oxidation conditions show that, for undoped LaTiO₃ films, the resistivity increases rapidly as background oxygen pressure is increased, which is consistent with the formation of the LaTiO_3+x phase. Sr doping of LaTiO₃ significantly enhances the conductivity of thin film materials when synthesized under oxidizing conditions. The transport behavior for Sr-doped LaTiO₃ films correlates with structural data showing no significant shift in lattice spacing as oxygen partial pressure is increased during film growth. In addition, the epitaxial growth of (La,Sr)TiO₃ on biaxially textured Ni alloy tapes is demonstrated. These results suggest that (La,Sr)TiO₃ is a viable candidate as a conducting buffer for superconducting film growth on biaxially textured metal tapes.     

硫化温度对Sn_xS_y薄膜光电性能的影响

用真空热蒸发技术在玻璃基片上沉积一层Sn薄膜,分别在硫化温度为210,240和270℃的条件下硫化45min。研究了硫化温度对薄膜样品光学和电学性能的影响。结果显示:随着硫化温度的升高,其电阻率减小;但薄膜导电类型不受硫化温度的影响,都为p型。当硫化温度为240℃时,薄膜为斜方SnS多晶薄膜,沿{111}方向优先生长,其均匀性和致密性以及对基片的附着力都较好,薄膜粒径为200～800nm,薄膜的直接能带间隙为1.46eV,电阻率为25.54Ω·cm。     

Effect of oxygen partial pressure on conductivity type of MgZnO nanocrystalline thin films prepared by metal-organic chemical vapor deposition

The properties of the MgZnO nanocrystalline thin films deposited on c-Al₂O₃ substrates by metal-organic chemical vapor deposition (MOCVD) at various oxygen partial pressures (Po₂) were thoroughly studied. It was found that the nanocrystalline films grown in the oxygen partial pressure range from 38 to 56 Pa were all c-axis oriented. From the atomic force microscope (AFM) images and photoluminescence (PL) spectra, we could also find that both the surface morphologies and the optical properties of the MgZnO nanocrystalline thin films depended on the oxygen partial pressure greatly. Hall effect measurements confirmed the conversion of conduction type of MgZnO under a certain range of oxygen partial pressure. With the increase of oxygen content, the crystallinity of MgZnO nanocrystalline thin films was degraded to polycrystalline and the p-type MgZnO was produced when the oxygen partial pressure was larger than 50 Pa. The hole concentration and mobility could reach to 9.71×10¹⁷ cm⁻³ and 2.44 cm² V⁻¹ s⁻¹, and the resistivity was 2.87 Ω cm while the oxygen partial pressure was 56 Pa.     

衬底温度和氮气分压对氮化锌薄膜的性能影响

采用射频磁控溅射法在不同衬底温度和不同氮气分压下在石英玻璃衬底上制备氮化锌薄膜. 利用XRD和喇曼散射仪分析了样品的晶体结构和组成. 结果表明当氮气分压为1/2时可以生成多晶单一相的氮化锌薄膜. 利用霍尔效应和光学透过谱测量了样品的电学和光学性质. 结果表明衬底温度对样品的电学和光学性质有很大的影响. 衬底温度从100℃上升到300℃时,样品的电阻率从0.49降低到0.023Ω·cm. 电子浓度从2.7×1016升高到8.2×1019cm-3. 在衬底温度为200℃,氮气分压为1/2时,样品的光学带隙为1.23eV.     

Cu2ZnSnS4 thin film solar cells by fast coevaporation

Solar cells based on kesterite‐type Cu₂ZnSnS₄ (CZTS) were fabricated on molybdenum coated soda lime glass by evaporation using ZnS, Sn, Cu, and S sources. The coevaporation process was performed at a nominal substrate temperature of 550°C and at a sulfur partial pressure of 2–3 × 10⁻³ Pa leading to polycrystalline CZTS thin films with promising electronic properties. The CZTS absorber layers were grown copper‐rich, requiring a KCN etch step to remove excess copper sulfide. The compositional ratios as determined by energy‐dispersive X‐ray spectroscopy (EDX) after the KCN etch are Cu/(Zn + Sn): 1.0 and Zn/Sn: 1.0. A solar cell with an efficiency of 4.1% and an open‐circuit voltage of 541 mV was obtained. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis and characterization of phosphorus-doped ZnO and (Zn,Mg)O thin films via pulsed laser deposition

The transport and optical properties of phosphorus-doped (Zn,Mg)O thin films grown via pulsed laser deposition (PLD) are studied. The carrier type of as-deposited (Zn,Mg)O:P films converts from n-type to p-type with increasing oxygen partial pressure. All the films exhibit good crystallinity with c-axis orientation. This result indicates the importance of oxidation conditions in realizing p-type (Zn,Mg)O:P films. The as-deposited ZnO:P film properties show a strong dependence on the deposition ambient at different growth temperatures. The resistivity of the samples deposited in O₃/O₂ mixture is two orders of magnitude higher than the films grown in oxygen and O₂/Ar/H₂ mixture. The room-temperature photoluminescence (PL) of the as-deposited films has been shown that growing in the O₂/Ar/H₂ mixture ambient significantly increases the band edge emission while inhibiting the visible emission. The enhanced ultraviolet (UV) emission in the films grown in O₂/Ar/H₂ mixture may result from hydrogen passivation of the deep level emission centers. The annealed ZnO:P films are n-type with nonlinear dependence of resistivity on annealing temperature. The resistivity increases in the films with annealing at 800°C while decreasing with further increasing annealing temperature. Strong visible light emission is observed from the ZnO:P films annealed in oxygen.     

Indium Tin Oxide Thin Films Grown on Polyethersulphone (PES) Substrates by Pulsed‐Laser Deposition for Use in Organic Light‐Emitting Diodes

High quality indium tin oxide (ITO) thin films were grown by pulse laser deposition (PLD) on flexible polyethersulphone (PES) substrates. The electrical, optical, and surface morphological properties of these films were examined as a function of substrate temperature and oxygen pressure. ITO thin films, deposited by PLD on a PES substrate at room temperature and an oxygen pressure of 15 mTorr, have a low electrical resistivity of 2.9×10^?4 Ω cm and a high optical transmittance of 84 % in the visible range. They were used as the anode in organic light‐emitting diodes (OLEDs). The maximum electro luminescence (EL) and current density at 100 cd/m² were 2500 cd/m² and 2 mA/cm², respectively, and the external quantum efficiency of the OLEDs was found to be 2.0 %.     

Effect of copper and chlorine on the properties of SiO2 encapsulated polycrystalline CdSe films

The effects of different copper doping concentrations on the properties of SiO₂ encapsulated CdSe films have been investigated. Two methods were used to dope the films with copper: ion implantation and diffusion from a surface layer. The room temperature dark resistivity of films annealed in oxygen at 450°C was found to increase as the copper concentration was increased until a maximum resistivity of 10⁸ ohm cm occurred at a copper concentration of 10²⁰ atoms cm⁻³. The room temperature resistivity in the light was found to be independent of the copper concentration and whether the films were annealed in argon or oxygen. During annealing the grains grew from 0.03 μm to 0.3 μm and this growth was independent of the doping or the annealing ambient. The energy levels, carrier mobilities, and microstructure of the annealed films were dependent on the method of doping. The ion implanted films had an additional energy level at 0.33 eV and their mobility was a factor of 4 smaller than films doped by the surface diffusion method, whose mobilities were 20 to 35 cm²V⁻¹ s⁻¹. The addition of chlorine to copper doped films had no effect on either the resistivity or photosensitivity but slowed the response times of the photocurrent by a factor of 10. No energy levels were observed which could be associated with the copper nor was the copper found to affect the density of the observed intrinsic levels at 0.65 and 1.1 eV.