Cu2O薄膜的制备与表征

以透明导电玻璃ITO和铜片为工作电极,用0.1mol/L乙酸铜和0.02mol/L乙酸钠的混合溶液作为电解液,通过两电极电化学沉积方法制备了Cu2O薄膜。讨论了pH值和沉积电位对Cu2O薄膜的影响,利用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、X射线光电子能谱(XPS)对薄膜进行表征。结果表明,两电极电化学沉积法制备Cu2O薄膜最佳的pH值为5.7～5.9,沉积电位为1.1～1.3V。此外,分析了沉积电位对Cu2O薄膜形貌的影响。     

单一取向Cu2O纳米棒的一种工业制备技术

作为一种直接带隙p型半导体材料,Cu2O在很多工业领域都有良好的应用前景,而Cu2O纳米棒因其一维纳米几何而具有更诱人的性能。然而缺少低成本的制备方式限制了Cu2O纳米棒的工业应用。为了解决这个问题,我们探索了热蒸发掠射角沉积加后退火处理的制备方法,成功获得了取向一致的多晶Cu2O纳米棒阵列薄膜,为Cu2O及类似材料的纳米棒薄膜的大规模工业化生产找到了一种低成本的制备技术。     

通过氧化Cu膜制备Cu_2O薄膜

通过热蒸镀Cu膜并在空气中退火制备Cu2O薄膜,利用X射线衍射(XRD)、能量分散X射线谱(EDX)和原子力显微镜(AFM)研究了已沉积和不同温度退火薄膜的晶体结构、成份和表面形貌。结果表明,Cu膜在200℃退火30分钟可以得到具有单一成份的Cu2O薄膜。四探针测量得到所制备的Cu2O薄膜电阻率为0.22Ωcm。用紫外可见光分光光度计(UV-vis)研究了Cu2O薄膜的光学特性,得出其光学带隙为2.4eV。     

Cu薄膜上热氧化法制备CuAl2O4薄膜北大核心CSCD

采用离子束辅助沉积方法在95%(质量比)Al2O3基板上制备Cu薄膜,利用热氧化法使Cu薄膜氧化,并与Al2O3基板反应,制备出CuAl2O4薄膜。通过X射线衍射仪、扫描电子显微镜、能谱仪和X射线光电子能谱仪分别对CuAl2O4薄膜的结构、成分和微观形貌进行了表征。研究结果表明,大气环境下,热氧化温度低于1000℃时,薄膜主要成分为CuO,随着热氧化温度的提升,薄膜成分比例并无较大变化,但是薄膜晶粒在不断增大;热氧化温度为1000℃时,氧化后的Cu薄膜与Al2O3基板开始反应形成CuAl2O4晶体。当热氧化温度为1100℃时反应更加完全,形成纯度较高的CuAl2O4薄膜,且薄膜晶粒尺寸明显增大,薄膜表面Al元素含量增加。     

前驱体温度对激光化学气相沉积YBa2Cu3O 7δ超导薄膜结构及性能的影响

采用激光化学气相沉积法在Al2O3基底上以49μm·h-1的沉积速率高速制备了c-轴取向的YBa2Cu3O 7-δ薄膜,其中,激光功率为133 W,沉积温度1103 K,腔体压强800 Pa。研究了前驱体蒸发温度及薄膜退火温度对薄膜电学性能的影响。研究表明,Ba、Cu、Y前驱体加热温度分别为603、478、459 K时制备的薄膜在经813 K高温热处理12 h后,临界温度可达83 K。     

沉积温度对N掺杂Cu_2O薄膜生长及光学特性的影响

利用反应射频磁控溅射技术,首次利用氧化铜作为溅射靶,在氮气和氩气的混合气氛下,制备出N掺杂的Cu2O薄膜。通过改变沉积温度,研究了氮掺杂Cu2O薄膜的结构特征和生长模式以及光学特性。研究结果表明低温沉积时,薄膜表现为比较强的（100）织构;随着沉积温度增加到500℃,薄膜逐渐转变为（111）织构,沉积温度增加导致的临界成核自由能的增加是决定薄膜织构特征的重要因素;原子力显微镜分析发现不同沉积温度的薄膜表面形貌的空间标度指数α〉1,属于表面扩散支配的薄膜生长机制;薄膜表面形貌的空间标度指数和关联长度随沉积温度的变化与薄膜织构度之间存在明显的关联;不同温度沉积的氮掺杂Cu2O薄膜的禁带宽度为（2.52±0.03）eV。     

氧化亚铜薄膜的研究进展

氧化亚铜（Cu2O）具有优越的光电性质，是一种具有广泛用途的材料，而且它的制备方法很多。结合最近的研究进展综述了Cu2O薄膜的制备方法与基本性质，分析了Cu2O薄膜研究开发现状，展望了Cu2O薄膜在太阳能电池应用方面的前景。     

纳米Cu2O/TiO2 异质结薄膜电极的制备和表征

通过阴极还原在纳米TiO2膜上电沉积Cu2O，获得了p-Cu2O／n-TiO2异质结电极．研究了沉积温度对Cu2O膜厚、纯度和形貌的影响，制备出纯度较高、粒径为40-50nm的Cu2O薄膜．纳米Cu2O膜在200℃烧结后透光性最好，禁带宽度为2．06eV．光电化学测试表明纳米p-Cu2O／n-TiO2异质结电极呈现较强的n-型光电流响应并且能够提高光电转换效率．     

离子束辅助沉积Al2O3薄膜的微观状态及其物理特性研究

本文利用透射电子显微镜、原子力显微镜、X光电子能谱等微观分析手段 ,系统研究了氧离子束辅助离子束沉积方法制备的Al2 O3 薄膜的化学成分、微观结构、表面形貌及其随退火温度的变化 ,并对Al2 O3 薄膜折射率、显微硬度和膜基结合强度等物理特性及其随沉积温度的变化进行了详细研究。研究发现 :用离子束辅助沉积制备的薄膜基本满足Al2 O3 的标准成分配比 ;在沉积温度低于 5 0 0℃制备的Al2 O3 薄膜以非晶Al2 O3 相a Al2 O3 为主 ;Al2 O3 薄膜的表面粗糙度、折射率、显微硬度随沉积温度的增加而增加 ;当沉积温度高于 2 0 0℃时 ,薄膜与基体间的膜基结合强度将随沉积温度的增加而下降。分析表明 :薄膜表面形貌与晶体内部的结构相变有关 ,薄膜的退火相变途径为a Al2 O380 0℃ γ Al2 O310 0 0℃ γ Al2 O3 +α Al2 O312 0 0℃ α Al2 O3 。     

Ta_2O_5薄膜制备的研究现状及进展

Ta2O5薄膜具有很好的电学性能和光学性能,制备方法种类繁多,如溶胶-凝胶法(Sol-gel)、化学气相沉积法、电子束蒸发技术、溅射法、Ta层阳极氧化或热氧化法、离子辅助沉积法(IBAD)、原子层沉积法(ALD)等。评述了现有各种制备方法的优缺点,综述了Ta2O5薄膜各种方法制备的条件、薄膜的功能性质等,并评析了金属有机化合物为前驱体制备性能优良的Ta2O5薄膜的前景。     

N掺杂Cu2O薄膜的低温沉积及快速热退火研究

采用氧化亚铜(Cu_2O)陶瓷靶,利用射频磁控溅射沉积法在氮气和氩气的混合气氛下制备了N掺杂Cu_2O(Cu_2O∶N)薄膜,并在N_2气氛下对薄膜进行了快速热退火处理,研究了N_2流量和退火温度对Cu_2O∶N薄膜的生长行为、物相结构、表面形貌及光电性能的影响。结果显示,在衬底温度300℃、N_2流量12sccm条件下生长的薄膜为纯相Cu_2O薄膜;在N_2气氛下对预沉积薄膜进行快速热退火处理不影响薄膜的物相结构,薄膜的结晶质量随退火温度(450℃)的升高而显著改善;快速热退火处理能改善薄膜的结晶质量和缺陷,降低光生载流子的散射,增强载流子的传输,预沉积Cu_2O∶N薄膜经400℃退火处理后展示出较好的电性能,薄膜的霍尔迁移率(μ)为27.8cm~2·V~(-1)·s~(-1)、电阻率(ρ)为2.47×10~3Ω·cm。研究表明低温溅射沉积和快速热退火处理能有效改善Cu_2O∶N薄膜的光电性能。     

(1-x)TiO_2-xTa_2O_5薄膜的光学性能研究

TiO2-Ta2O5薄膜是较新颖的光学薄膜,由均匀混合的两种化合物薄膜材料作为膜料研制而成,本文采用离子辅助蒸发的方法,以不同配比的Ta2O5和TiO2混合物为初始膜料在K9玻璃上制备了TiO2-Ta2O5混合薄膜,并对其光学性能进行研究.实验结果表明,TiO2-Ta2O5薄膜在可见光范围内有较高的透射率,消光系数在10-3～10-4数量级,折射率在1.80～2.07范围内变化(550nm),是理想的光学镀膜材料.随着Ta2O5含量从0增加到20%,光学带隙从3.266eV单调增加到3.417eV,并用Kayanuma提出的模型解释了透射谱中吸收边的漂移现象.     

The growth of Cu thin films by low pressure chemical vapor deposition

We study the growth of Cu films en route to the production of CuInSe₂ thin films as absorber layers in solar cells by a low pressure chemical vapor deposition technique. In order to obtain good quality films, the deposition conditions such as substrate, source temperatures, concentration ratio of Ar to H₂ have been optimized. The surface morphology and structural analysis of Cu films have been carried out. It is revealed that annealing resulted in a change in the properties of the films and also in the generation of other phases such as -Cu₅Si (cubic) and CuO (monoclinic). ©1999Kluwer Academic Publishers     

Optical evidence for reactive processes when embedding Cu nanoparticles in Al(2)O(3) by pulsed laser deposition

The optical response of nanocomposite thin films formed by Cu nanoparticles (NPs) embedded in amorphous aluminium oxide (Al(2)O(3)) prepared by pulsed laser deposition (PLD) in vacuum is studied in order to investigate the possible existence of reactive processes on the Cu NPs during their covering with Al(2)O(3). The study is performed as a function of the laser fluence on the Al(2)O(3) target (0.6-4.6?J?cm(-2)), while the laser fluence for Cu ablation is kept constant (1.8?J?cm(-2)). The structural analysis of the films shows that they are formed by a high density of NPs with average dimensions in the 4.9-5.9?nm range. The optical response of the films has been followed in situ by real-time reflectivity measurements at 633?nm and after deposition by transmission measurements as a function of wavelength around the surface plasmon resonance (SPR). For low laser fluences on the Al(2)O(3) target, the absorption spectrum is dominated by a well-defined SPR absorption band at 1.9?eV. As the laser fluence is increased, the intensity of the absorption band associated with the SPR decreases and shifts to 2.1?eV. The films deposited at low fluences contain metallic Cu NPs and, as the laser fluence increases sputtering of Cu from the NPs and mixing of the species from the Al(2)O(3) deposition with the Cu from the NPs surface takes place. The latter process leads to the formation of an Al-Cu oxide cover on the Cu NPs. The present results provide evidence for mixing of species from the host and Cu at the surface of the NPs, and it is shown how the degree of mixing depends on the laser fluence used to ablate the Al(2)O(3) host target.     

Low cost CuInSe2 thin films production by stacked elemental layers process for large area fabrication of solar cell application

Low cost deposition of large area CuInSe₂ (CIS) thin films have been grown on Mo-coated glass substrate by simple and economic stacked elemental layer deposition technique in vacuum. The grown parameters such as concentration of Cu, In and Se elements have been optimized to achieve uniform thin film in vacuum chamber. The as-grown Cu/In/Se stacked layers have been annealed at 200 °C and 350 °C for 1 h in air ambient. The as-grown and annealed films have been further subjected to characterization by X-ray diffraction (XRD), optical absorption, atomic force microscopy (AFM) and I-V measurement techniques. XRD patterns revealed that as-grown Cu/In/Se stacked layers represent amorphous nature while annealed CIS film reproduces nano-polycrystalline nature with chalcopyrite structure. The optical band gap of annealed films increases with respect to air annealing which confirms the reduction of crystallite size. Surface morphology of as-grown Cu/In/Se stacked layers and annealed CIS thin films have been confirmed by AFM images. The electrical measurements show enhancement of conductivity which is useful for solar cell application.     

Direct formation of wafer scale graphene thin layers on insulating substrates by chemical vapor deposition

Direct formation of high-quality and wafer scale graphene thin layers on insulating gate dielectrics such as SiO(2) is emergent for graphene electronics using Si-wafer compatible fabrication. Here, we report that in a chemical vapor deposition process the carbon species dissociated on Cu surfaces not only result in graphene layers on top of the catalytic Cu thin films but also diffuse through Cu grain boundaries to the interface between Cu and underlying dielectrics. Optimization of the process parameters leads to a continuous and large-area graphene thin layers directly formed on top of the dielectrics. The bottom-gated transistor characteristics for the graphene films have shown quite comparable carrier mobility compared to the top-layer graphene. The proposed method allows us to achieve wafer-sized graphene on versatile insulating substrates without the need of graphene transfer.     

工艺参数对纳米颗粒Cu/SiO_2复合薄膜结构和光谱特性的影响

用离子束溅射法制备了具有反常光吸收特性的纳米颗粒CU／SiO2复合薄膜。获得了在离子来参数一定时，基片温度、膜料的沉积时间和镀膜后的保温时间等工艺参数对这种薄膜结构和光学特性的影响规律，并对纳米颗粒Cu／SiO2复合薄膜的反常光吸收特性作了计算和解释。     

铜及其氧化物薄膜对大肠杆菌的强抑制作用

采用直流磁控溅射,靶材为金属铜靶,调节氧气和氩气流量,制备了以石英玻璃为基底颗粒大小在20～50nm之间的Cu和Cu2O纳米薄膜,研究了大肠杆菌与纳米铜系氧化物薄膜的相互作用。通过紫外可见分光光度计,掠入射小角X射线衍射(GIXRD),SEM分别对样品的光学性能、晶体结构、形貌特征进行了研究,发现纳米Cu和Cu2O薄膜均对大肠杆菌具有强抑制作用。在光照下,Cu2O薄膜除了具有金属离子抗菌效应外,光催化抗菌效应表现强烈;Cu薄膜表面有部分被氧化为Cu2O,有助于协同抗菌。     

Raman,photoluminescence analysis on Cu(InAl)Se2 thin films and the fabrication of Cu(InAl)Se2 based thin film solar cells

Cu(InAl)Se₂ (CIAS) thin films have been prepared by chemical bath deposition technique. Thickness of the prepared films has been measured by gravimetric technique. The structure, composition and optical transition as well as bandgap have been estimated by X-ray diffraction, energy dispersive X-ray analysis and spectrophotometer analysis. Raman analysis has been made on the prepared CIAS thin films to assign the fundamental lattice mode and to confirm the films crystallinity and stoichiometry. PL analysis has been carried out to find the effective mass of holes and electron, dielectric constant, the involved defects and their activation energy. Cu(InAl)Se₂-based solar cells with different types of buffer layers such as CdS, CdS:Cu, CdS:In were fabricated. The current and voltage were measured using an optical power meter and an electrometer and the fabricated solar cells were illuminated using 100 mW/cm² white light under AM1 conditions.     

电子束反应蒸发氧化物薄膜的应力特性

研究了反应电子束蒸发氧化物光学薄膜在空气中的应力。为了找到能减小多层膜结构内应力的淀积工艺参数,测试了氧化物膜层TiO2,Ta2O5,SiO2,Al2O3,HfO2的应力,发现有些膜层为压应力,一些高折射率膜为张应力。实验表明,热处理可以有效地降低氧化物膜层光学吸收,并改变应力。