Properties of ITO：Zr films deposited by co-sputtering

ITO：Zr films were deposited on glass substrate by co-sputtering with an ITO target and a Zirconium target. Substrate temperature and oxygen flow rate have important influences on the properties of ITO：Zr films. ITO：Zr films show better crystalline structure and lower surface roughness. Better optical-electrical properties of the films can be achieved at low substrate temperature. The certain oxygen flow rates worsen the electrical properties but can enhance the optical properties of ITO：Zr films. The variation in optical band gap can be explained on the basis of Burstin-Moss effect.     

一种新型透明导电氧化物薄膜—ITO∶Ta

利用磁控溅射,在玻璃基底上沉积了ITO∶Ta薄膜。研究了在不同衬底温度下ITO和ITO∶Ta薄膜的光电性能。高价金属元素Ta掺杂促进薄膜晶化的同时,导致了(400)晶面择优取向的形成。低温沉积的ITO∶Ta薄膜比ITO薄膜展示了较好的光电性能,Ta掺杂使得室温沉积ITO薄膜的效益指数分别由0.003×10-3Ω-1上升到了0.880×10-3Ω-1。透射谱表明,参数的变化引起明显的Burstin-Moss效应,通过直接跃迁的模型研究了光学禁带的变化。     

退火温度对ZnO掺杂ITO薄膜性能的影响

利用电子束蒸镀方法,在K8玻璃衬底上沉积ZnO掺杂ITO(ZnO-ITO)与ITO薄膜。研究不同退火温度对ZnO-ITO薄膜的微观结构的影响;对比分析了在不同退火温度条件下,ZnO-ITO和无掺杂ITO薄膜的光电性能。结果发现,ZnO-ITO薄膜具有较大的晶粒尺寸,随着退火温度的上升,晶体结构得到改善,表面粗糙度减小,薄膜的光电性能显著提高。ZnO-ITO薄膜经过500℃退火后得到最佳的综合性能,其表面均方根粗糙度(RMS)为32.52nm,电阻率为1.43×10-4Ω.cm;对442nm波长的光,透射率可达98.37%;与ITO薄膜相比,ZnO-ITO薄膜具有显著的抗PEDOT:PSS溶液腐蚀的能力。     

快速光退火对ITO薄膜结构和性能的改善

利用电子束蒸发技术在常温下制备ITO透明导电膜,在这种条件下很难得到性能良好的透明导电膜,试图通过研究快速光热退火下退火温度、退火时间对其性能的影响,致力于在低温退火工艺下改善薄膜性能.通过对退火后样品禁带宽度的计算得出随着退火温度或退火时间的增大,禁带宽度逐渐增大;对样品的微结构分析发现随着退火温度的提高或退火时间的延长,样品的微结构致密性提高,各晶向面间距和晶格常数逐渐趋于标准的晶体;但退火温度过高或退火时间过长反而不利于透明导电膜性能的提高,所以选取合适的退火温度和退火时闻是光退火下透光性和导电性都得到提升的关键.在200℃的退火温度下,退火12 min可实现样品的透光率在可见光范围内达到82%,电阻率ρ＝2.3×10-3Ω·cm.     

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 %.     

工艺条件对柔性衬底ITO薄膜光电性能的影响

采用直流磁控溅射法在柔性衬底上镀制ITO透明导电薄膜,全面研究了薄膜厚度、氧气流量、溅射速率、溅射气压和镀膜温度等工艺条件对ITO薄膜光电性能的影响。结果表明,当膜厚大于80nm、氧氩体积比为1∶40、溅射速率为5nm/min、溅射气压在0.5Pa左右、镀膜温度为80～160℃时,ITO薄膜的光电性能较好,其电阻率小于5×10–4?·cm、可见光透光率大于80%。     

PLD法制备ITO导电薄膜及其性能

为了研制可用于高温环境下进行应变测量的应变层,采用脉冲激光沉积(PLD)法在陶瓷基底上制备了氧化铟锡(ITO)薄膜.研究了PLD法中不同基底温度对ITO薄膜显微结构、电学性能以及阻温特性的影响.采用X射线衍射仪(XRD)测试了薄膜的晶体结构,通过四点探针测量法测得薄膜的薄层电阻,采用场发射扫描电子显微镜(FESEM)对...     

溶胶-凝胶法制备ITO薄膜的光电性能研究

采用溶胶-凝胶旋转涂膜工艺,在普通玻璃基片上制备了掺锡氧化铟(ITO)纳米透明导电薄膜。采用紫外-可见透射光谱和四探针技术,研究了不同Sn掺杂量、不同热处理温度和热处理时间以及不同涂层对薄膜光学和电学性能的影响。结果表明薄膜的方块电阻随Sn掺杂量的增大和热处理温度的升高先降低后增加,在适宜的温度范围内薄膜在可见光区平均透过率随热处理温度升高而增加。在一定的温度下,随着热处理时间的延长,ITO薄膜的方块电阻先降低后增加,透射率先增加后降低。在最佳工艺条件下,采用溶胶-凝胶法制备的ITO薄膜平均可见光透过率达86%,薄膜方阻为322Ω/□。     

Influence of oxygen flow rate on microstructural,electrical and optical properties of indium tin tantalum oxide films

Indium tin oxide (ITO) and indium tin tantalum oxide (ITTO) films were deposited on glass substrates by magnetron sputtering technology with one or two targets. Properties of ITO and ITTO films deposited at different oxygen flow rates were contrastively studied. Ta-doping strengthens along the orientation of (400) plane and leads to better crystalline structure as well as to a decrease in surface roughness. The increase in oxygen flow rate increases sheet resistance and reduces carrier concentration, and ITTO films show higher carrier concentration. Certain oxygen flow rates can improve the visible light transmittance of films, but excessive oxygen can worsen the optical properties. The carrier concentration has an important influence on near-IR reflection, near-UV absorption and optical band gap. The optical band gap decreases with the increasing of oxygen flow rate, and ITTO films show wider optical band gap than ITO films. ITTO films prepared by co-sputtering reveal better optical–electrical properties and chemical and thermal stability than ITO films.     

低翘曲度ITO透明导电膜玻璃的工艺研究

研究了不同厚度ITO膜的大尺寸超薄导电玻璃的翘曲度,ITO膜形成期间基片温度对ITO膜层晶体化程度的影响及不同基片温度下形成的ITO膜层在不同的退火条件下的退火前、后的电阻率和膜压应力.实验发现,ITO膜层的很高的压应力是导致导电膜玻璃翘曲的直接原因;采用室温沉积非晶ITO膜,然后经高温热退火可获得低膜压应力多晶相ITO膜.基于实验结论,提出了一种适合批量生产的低翘曲度ITO膜导电玻璃的制备工艺.     

ITO衬底上LiTaO3薄膜的制备与介电特性

用溶胶凝胶法在ITO衬底上制备了钽酸锂(LiTaO3)薄膜,利用XRD、SEM和AFM对薄膜的晶向、表面形态等作了表征;研究了不同溶剂对LiTaO3溶胶稳定性的影响和不同退火条件对LiTaO3薄膜结晶的影响;利用Al/LiTaO3/ITO结构,测试了薄膜的介电系数和介电损耗.结果表明:每层薄膜都晶化退火比交替使用焦化、结晶退火能生长出质量更好的LiTaO3薄膜;频率1KHz时,介电损耗约0.4,相对介电系数约53.并讨论了介电损耗增大的原因.     

二氧化锡覆盖层对ITO透明导电薄膜热稳定性的改良

采用射频磁控溅射法在ITO玻璃表面沉积了一层15 nm左右的SnO2薄膜。利用霍尔效应测试仪、四探针电阻测试仪、场发射电子显微镜及紫外–可见–近红外光谱仪分析了所制薄膜的电学性质、表面形貌和光学性质。结果表明,在300~600℃退火后镀有SnO2覆盖层的ITO(SnO2/ITO)薄膜具有相对好的热学稳定性。在600℃退火后,ITO薄膜的方阻和电阻率分别为88.3Ω/□和2.5×10–3.cm,而此时,SnO2/ITO薄膜的方阻和电阻率仅为43.8Ω/□和1.2×10–3Ω.cm。最后,阐述了SnO2覆盖层提高ITO薄膜热稳定性的机制。     

Annealing and light effect on optical and electrical properties of ZnS thin films grown with the SILAR method

Zinc sulphide (ZnS) thin films were grown on glass substrates by the Successive Ionic Layer Adsorption and Reaction (SILAR) technique at room temperature and ambient pressure. Surface morphologies of grown films were characterized using scanning electron microscopy (SEM). The crystal structure and crystal size of the thin films were characterized by the X-ray diffraction (XRD) method and found that the films exhibit polycrystalline characterization. The optical absorption measurements were done as a function of the temperature at 10–320 K temperature range. Using absorption measurements, the band gap energies were calculated at 10 and 320 K, as 3.83 and 3.72 eV, respectively. The annealing temperature effect on optical band gap and the light effect on the electrical properties of ZnS thin films were investigated and it was found that the current increased with increasing light intensity. The annealed films were found have more resistance than the as-grown film.     

Effect of thermal annealing on physical properties of vacuum evaporated In2S3 buffer layer for eco-friendly photovoltaic applications

The present communication reports the effect of thermal annealing on the physical properties of In₂S₃ thin films for eco-friendly buffer layer photovoltaic applications. The thin films of thickness 150 nm were deposited on glass and indium tin oxide (ITO) coated glass substrates employing thermal vacuum evaporation technique followed by post-deposition thermal annealing in air atmosphere within a low temperature range 150–450 °C. These as-deposited and annealed films were subjected to the X-ray diffraction (XRD), UV–vis spectrophotometer, current–voltage tests and scanning electron microscopy (SEM) for structural, optical, electrical and surface morphological analysis respectively. The compositional analysis of as-deposited film is also carried out using energy dispersive spectroscopy (EDS). The XRD patterns reveal that the as-deposited and annealed films (≤300 °C) have amorphous nature while films annealed at 450 °C show tetragonal phase of β-In₂S₃ with preferred orientation (109) and polycrystalline in nature. The crystallographic parameters like lattice constant, inter-planner spacing, grain size, internal strain, dislocation density and number of crystallites per unit area are calculated for thermally annealed (450 °C) thin films. The optical band gap was found in the range 2.84–3.04 eV and observed to increase with annealing temperature. The current–voltage characteristics show that the as-deposited and annealed films exhibit linear ohmic behavior. The SEM studies show that the as-deposited and annealed films are uniform, homogeneous and free from crystal defects and voids. The grains in the thin films are similar in size and densely packed and observed to increase with thermal annealing. The experimental results reveal that the thermal annealing play significant role in the structural, optical, electrical and morphological properties of deposited In₂S₃ thin films and may be used as cadmium-free eco-friendly buffer layer for thin films solar cells applications.     

Low-pressure H2/N2 annealing on indium tin oxide film

Annealing of indium tin oxide (ITO) film in low-pressure H₂/N₂ was investigated. On carefully selecting the annealing process window, apparent electrical property improvement as well as good optical property can be obtained. It was found that ITO annealed with 2 Pa, H₂/N₂:6/6 sccm, at 500 °C for an hour can increase its electrical conductivity 60% more than ITO without annealing, 58% more than ITO annealed with pure H₂. An annealed ITO without specially selected recipe can easily possess worse electrical and optical properties than that without annealing. It can be explained that annealing ITO in a hydrogen-contained environment can lead to hydrogen reduction–oxygen vacancy playing a donor role in ITO; however, annealing also provides the energy to remove ITO material defects including donors.     

Effect of annealing on the structural, optical and electrical properties of ITO films by RF sputtering under low vacuum level

Indium tin oxide (ITO) thin films were prepared by RF sputtering of ceramic ITO target in pure argon atmosphere at a high base pressure of 3×10⁻⁴ mbar without substrate heating and oxygen admittance. The use of pure argon during deposition resulted in films with high transparency (80-85%) in the visible and IR wavelength region. The films were subsequently annealed in air in the temperature range 100-400 °C. The annealed films show decreased transmittance in the IR region and decreased resistivity. The films were characterized by electron microscopy, spectrophotometry and XRD. The predominant orientation of the films is (2 2 2) instead of (4 0 0). The transmission and reflection spectra in the wavelength range 300-2500 nm are used to study the optical behaviour of the films. The optical transmittance and reflectance spectra of the films were simultaneously simulated with different dielectric function models. The best fit of the spectrophotometric data was obtained using the frequency-dependent damping constant in the Drude model coupled with the Bruggeman effective medium theory for the surface roughness. It has been found that the sputtering power and the chamber residual pressure play a key role in the resulting optical properties. This paper presents the refractive index profile, the structure determined from the XRD and the electrical properties of ITO films. It has been found from the electrical measurement that films sputtered at 200 W power and subsequently annealed at 400 °C have a sheet resistance of 80 Ω/□ and resistivity of 1.9×10⁻³ Ωcm.     

离子注入对ITO薄膜电学特性的影响

对系列In2O3∶Sn (ITO)薄膜样品分别实施了不同剂量的Sn+, Ag+ 和Mo+离子注入并将它们在250 ℃下进行了热处理.利用霍耳测量研究了原始样品及注入和退火前后各样品的电学特性.研究了ITO薄膜的电学参数受离子注入的种类及剂量的影响.实验证明不同种类的离子注入会不同程度地降低ITO的导电性能,但热处理的效应与之相反.3种金属中,Sn+离子对薄膜造成的注入损伤最小,而高价的钼离子可以替换铟离子的位置成为施主,当注入剂量为1×1015 cm-2时,经过Mo+离子注入和后续退火的ITO薄膜,载流子浓度提高了14%.     

Effect of post deposition heat treatment on microstructure parameters,optical constants and composition of thermally evaporated CdTe thin films

Thin film microstructure and its properties can be effectively altered with post deposition heat treatments. In this respect, CdTe thin films were deposited on glass substrates at a substrate temperature of 200 °C using thermal evaporation technique, followed by air annealing at different temperatures from 200 to 500 °C. Structural analysis reveals that CdTe thin films have a cubic zincblend structure with two oxide phases related to CdTe₂O₅ and CdTeO₃ at annealing temperature of 400 and 500 °C respectively. Regardless of the annealing temperature, the plane (111) was found to be the preferred orientation for all films. The crystallite size was observed to increase with annealing temperature. All films were found to display higher lattice parameters than the standard, and hence found to carry a compressive stress. Optical measurements suggest high uniformity of films both before and after post deposition heat treatment. Films annealed at 400 °C displayed superior optical properties due to its high refractive index, optical conductivity, relative density and low disorder. Furthermore, according to the compositional measurements, CdTe thin films were found to exhibit Te rich and Cd rich nature at regions near the substrate and center of the film respectively, for all annealing temperatures. However, composition of the regions near the substrate was found to become more Te rich with increasing annealing temperature. The study suggests that changing the annealing temperature as a post deposition treatment affects structural and optical properties of CdTe thin film as well as its composition. According to the observations, films annealed at 400 °C can be concluded to be the best films for photovoltaic applications due to its superior optical and structural properties.     

Effect of annealing temperature on structural,electrical and optical properties of spray pyrolytic nanocrystalline CdO thin films

Nanocrystalline CdO thin films were prepared onto a glass substrate at substrate temperature of 300 °C by a spray pyrolysis technique. Grown films were annealed at 250, 350, 450 and 550 °C for 2.5 h and studied by the X-ray diffraction, Hall voltage measurement, UV-spectroscopy, and scanning electron microscope. The X-ray diffraction study confirms the cubic structure of as-deposited and annealed films. The grain size increases whereas the dislocation density decreases with increasing annealing temperature. The Hall measurement confirms that CdO is an n-type semiconductor. The carrier density and mobility increase with increasing annealing temperature up to 450 °C. The temperature dependent dc resistivity of as-deposited film shows metallic behavior from room temperature to 370 K after which it is semiconducting in nature. The metallic behavior completely washed out by annealing the samples at different temperatures. Optical transmittance and band gap energy of the films are found to decrease with increasing annealing temperature and the highest transmittance is found in near infrared region. The refractive index and optical conductivity of the CdO thin films enhanced by annealing. Scanning electron microscopy confirms formation of nano-structured CdO thin films with clear grain boundary.     

Optimization of physical properties of vacuum evaporated CdTe thin films with the application of thermal treatment for solar cells

This paper reports the optimization of physical properties of cadmium telluride (CdTe) thin films with the application of thermal treatment. The films of thickness 650 nm were deposited on glass and indium tin oxide (ITO) coated glass substrates employing vacuum evaporation followed by thermal annealing in the temperature range 250–450 °C. The films were characterized using X-ray diffraction (XRD), source meter and atomic force microscopy (AFM) for structural, electrical and surface topographical properties respectively. The X-ray diffraction patterns reveal that films are polycrystalline with predominant zinc-blende structure having preferred reflection (111). The structural parameters are calculated and discussed in detail. The current–voltage characteristics show Ohmic behavior and the electrical conductivity is found to increase with annealing treatment. The AFM studies show that the surface roughness of films is observed to increase with annealing. The experimental results reveal that the thermal annealing plays an important role to enhance the physical properties of CdTe thin films and annealed films may be used as absorber layer in CdTe/CdS solar cells.