溶胶凝胶法混合掺杂SnO2薄膜的返回特性研究

在常温、加温和光照三种环境下,通过采用溶胶凝胶法在玻璃基片上制备成的混合掺杂Cu_TiO2和Fe_TiO2的SnO2薄膜在乙醇、丙酮两种气氛作用下进行气敏反应前后的光反射谱测试,研究薄膜的返回特性。研究分析表明,掺杂SnO2薄膜在常温返回特性不理想,在100℃加温3分钟和红外线光照10分钟后,掺杂SnO2薄膜测试光反射谱表明返回特性表现良好,能在较短时间和较宽波段内返回。     

退火处理对SnO2:F薄膜光电性能的影响

SnO2∶F薄膜作为low-e玻璃的表面功能层材料,广泛应用于节能镀膜玻璃。Low-e玻璃在后期退火(深加工)后,其性能的变化已经引起了学术研究和实际应用方面的的关注。我们对于用化学气相沉积法在玻璃表面沉积的约250nm厚的SnO2∶F薄膜进行不同的退火处理。并通过一系列的研究,结果发现,薄膜的结构、组成、电学、光学性能在氮气和空气两种不同的退火气氛下会有显著的变化。SnO2∶F薄膜的Low-e性能经过空气中高温退火后下降明显。通过计算对比退火后SnO2∶F薄膜的晶格常数和晶胞尺寸,提出了一种对于薄膜Low-e性能下降的合理解释。     

SnO2掺杂对MnZn铁氧体微观结构和性能的影响

采用氧化物陶瓷工艺制备MnZn功率铁氧体,研究了SnO2掺杂对MnZn功率铁氧体微观结构及磁性能的影响。结果表明添加适量的SnO2可以有效提高晶粒均匀性和致密度。随着SnO2添加量的增加,起始磁导率先上升后下降,磁损耗先下降后上升。当添加量为0.5%(摩尔分数)时,μi达到最大值,损耗最低。此外,铁氧体损耗最低点所对应的温度随着SnO2掺杂量的增加向低温移动。通过对比一次掺杂和二次掺杂,发现一次掺杂的SnO2主要作用于晶粒内部,二次掺杂的SnO2主要作用于晶界处,而且一次掺杂所获得的样品性能更优。     

反应磁控溅射制备SnO2薄膜及其微观形貌与光致发光性能研究

利用反应磁控溅射法(RMS)制备了SnO_2薄膜,并研究了溅射参数对薄膜微观结构和光学性能的影响。结果表明,随着溅射气压、氧分压的增大和衬底温度的升高,薄膜沉积速率相应减小;在不同衬底温度下(室温至600℃)溅射薄膜时,较高的衬底温度可得到较大的SnO_2晶粒,表面更为粗糙;此外,将原生SnO_2薄膜在O_2气氛下退火可以改善其结晶度,原本的柱状结构转变成致密的薄膜结构,其光学禁带宽度变宽至3.85eV;经过退火的SnO_2薄膜的光致发光(PL)强度显著增强,位于约610nm的PL发光峰主要是源于SnO_2纳米晶体表面悬挂键的未饱和电子态。     

SnO2纳米颗粒制备及其对溶胶-凝胶Sb:SnO2薄膜性能的影响

以Sn(OEt)2为起始原料,采用水热晶化法合成了分散性良好的金红石结构的SnO2纳米颗粒.采用X射线衍射对其进行了表征,表明SnO2纳米颗粒的结晶性良好,颗粒尺寸小于10nm.将合成的SnO2纳米颗粒均匀分散到SbSnO2镀膜液中,经陈化后制成镀膜溶胶,以溶胶-凝胶浸渍镀膜工艺制备纳米颗粒掺杂SbSnO2薄膜.分别采用范德堡(Van Der Pauw)法、UV/VIS分光光度计和FTIR中红外分析仪测量并分析膜层的导电性能、光学性能及结构特征,研究了导电纳米颗粒添加对SbSnO2薄膜电性能、光学性能和结构的影响.     

超声热解法制备SnO2:F薄膜加热管及其性能研究

采用超声喷涂热解淀积方法将SnO2F透明导电薄膜制备于耐高温的硼硅玻璃管内壁.XRD物相分析及SEM、STM形貌分析表明,SnO2F薄膜为多晶结构,平均粒径50nm.分析了薄膜中F取代SnO2中O的形成过程和薄膜电导率增强的机理,解释了不同的工艺条件对薄膜的结构、光电特性的影响,确定了制备SnO2F薄膜加热管的最佳工艺条件.该条件下制备的薄膜的电阻率达4×10-4Ω·cm,可见光透过率高于90%,功率密度平均可达35 W/cm2.     

磁控溅射制备铝掺杂氮化铜薄膜的结构及光电性能研究

以高纯铜和铝为靶材,氮气和氩气分别为源气体和工作气体,采用双靶共溅射磁控技术在单晶硅和石英片上制备了铝掺杂氮化铜(Cu₃N:Al)薄膜。对Cu₃N:Al薄膜的表面形貌、晶体结构、光透射性能和电学性能等进行表征、分析。研究结果表明,掺杂Al原子进入Cu₃N晶格空位;随着Al靶的直流溅射功率增大,Cu₃N:Al薄膜中Al含量增加;Al掺杂使得薄膜颗粒尺寸增大,薄膜表面变得粗糙。Cu₃N:Al薄膜表现为半导体特性,其光学带隙范围在1.41-1.80 eV;Al掺杂后,Cu₃N薄膜的光学带隙减小,其原因是掺杂Al原子改变了晶体内非平衡载流子寿命,导致薄膜的光学带隙降低。可见,通过调控Cu₃N薄膜中掺杂金属原子含量,可实现对其光电特性的调制。     

SiO2缓冲层对溶胶-凝胶法制备的SnO2∶Sb薄膜光电性能的影响

以SnCl2·2H2O和SbCl3为原料,利用溶胶-凝胶法制备了SnO2∶Sb薄膜。利用XRD观察了薄膜的结构特点,利用紫外可见分光光度计测量了薄膜的透过率,利用四探针测试系统表征了薄膜的电学性能。讨论了掺杂浓度以及SiO2缓冲层厚度对薄膜光电性能的影响。结果表明,随着掺杂浓度的增大,薄膜的电阻率先降低而后略有升高,当掺杂浓度为5%时,薄膜电阻率达到最小,为8.7×10-3Ω·cm;并深入研究了缓冲层对薄膜性能的改善作用:当掺杂浓度为5%时,随着缓冲层数的增加,薄膜方块电阻呈下降趋势,最小可达到95Ω/□,电阻率达到1.1×10-3Ω·cm。     

溅射功率对镓掺杂氧化锌薄膜光电性能的影响

本文利用射频磁控溅射的方法首次制备了厚度小于200 nm的低电阻率高透过率的镓掺杂ZnO(GZO)薄膜.研究了溅射功率的改变对GZO薄膜光电性能的影响.利用扫描电镜对薄膜的微观结构进行了观察,利用四探针测试仪、紫外-可见分光光度计对GZO薄膜的光电性能进行了测试.实验结果表明:薄膜电阻率随溅射功率增大而迅速下降,从46...     

ZnO-Nb2O5掺杂SnO2基陶瓷研究

通过常压烧结制备SnO2基陶瓷,研究了ZnO、Nb2O5单掺杂及ZnO-Nb2O5复合掺杂对SnO2基陶瓷的烧结性能及电阻率的影响。采用SEM及XRD对试样分别进行了微观结构观察及物相分析。研究表明,掺杂ZnO能提高陶瓷的体积密度,但对于降低电阻率的影响不明显,当ZnO掺杂量在0.5%～0.75%(质量分数)时,SnO2基体积密度可达到6.67～6.73g/cm3;掺杂Nb2O5不能有效提高烧成陶瓷的体积密度,但能显著降低SnO2基陶瓷的电阻率;0.5%(质量分数)ZnO～1.5%(质量分数)Nb2O5复合掺杂在1450℃下烧成的陶瓷可得到较好的性能,其体积密度可达到6.61g/cm3,常温电阻率为867.84Ω.cm。     

NiO/Ag/NiO透明导电膜光电特性研究

在室温条件下, 利用磁控溅射法在玻璃衬底上制备了NiO/Ag/NiO透明导电膜, 研究了不同NiO层和Ag层厚度对三层膜可见光透过率和电阻特性的影响。结果分析表明:制备的NiO/Ag/NiO为N型透明导电膜。在400~800 nm的可见光区域内, 随着NiO和Ag层厚度的增加, 薄膜的透光率先增大后减小。NiO层厚度为30 nm且Ag层厚度为11 nm时, 叠层膜具有较好的光学特性, 其最大透过率为84%, 薄膜电阻为3.8Ω/sq, 载流子浓度为7.476×10²¹cm^-3。对薄膜透过率进行了计算机模拟, 发现结果与实验中大致趋势相同, 但因为折射率选择和薄膜界面等因素的影响, 在可见光区域后半段实验值大于计算值。     

氧化锡薄膜场致发射研究

利用直流磁控反应溅射法,制备氧化锡薄膜,利用扫描电镜等方法对氧化锡薄膜微观结构进行分析。在低真空下,对不同厚度的氧化锡薄膜进行场致发射测试,结果显示,在氧化锡薄膜厚度为60nm时,场致发射性能最佳,当电流密度为10μA/m2时,开启电压为4.5 V/μm,阴阳两极电场为7 V/μm时,有较佳的场发射密度,同时发光亮度达到2180 cd/m2,结果表明,氧化锡薄膜在场发射平板显示及真空电子器件方面具有较好的应用潜力。     

Polarization dependence of the optical response in SnO2 and the effects from heavily F doping

The optical properties of intrinsic SnO₂ (TO) and fluorine doped (FTO) are characterized in terms of the dielectric function ε(ħω) = ε₁(ħω) + iε₂(ħω) by electronic structure calculations. The intrinsic TO shows intriguing absorption characteristics in the 3.0–8.0 eV region: (i) the low energy region of the fundamental band gap (3.2 < ħω < 3.9 eV), the optical transitions Г₃⁺ → Г₁⁺ (valence-band maximum to conduction-band minimum) is symmetry forbidden, and the band-edge absorption is therefore extremely weak. (ii) In the higher energy region (3.9 < ħω < 5.1 eV) the Г₅⁻ → Г₁⁺ transitions (from the second uppermost valence band) is strongly polarized perpendicular to the main c axis. (iii) Transitions with polarization axis parallel to c axis are generated from Г₂⁻ → Г₁⁺ transitions (from the third uppermost valence bands), and dominates at high energies (5.1 < ħω eV). Heavily F doped TO (FTO) with doping concentrations n_F = 4 × 10²⁰ cm^− 3 changes the absorption significantly: (iv) Substitutional F_O generates strong inter-conduction band absorption at 0.8, 2.2, and 3.8 eV which affects also the high frequency dielectric constant ε_∞. (v) Interstitial F_i is inactive as a single dopant, but act as a compensating acceptor in highly n-type FTO. This explains the measured non-linear dependence of the resistivity with respect to F concentration.     

硒化方式对CuInSe2薄膜结构、成分和形貌的影响

采用直流磁控溅射技术,首先在玻璃衬底上制备Mo薄膜,然后制备CuIn预制层。以固态硒粉为硒源,采用硒薄膜法和硒蒸气法两种硒化工艺,经过三步升温硒化方式对CuIn预制膜进行硒化制备CuInSe2薄膜。通过X射线衍射、能量散射谱和扫描电镜测试分析手段,分析CuIn预制膜和每一步硒化热处理后薄膜结构和形貌的变化。结果表明:两种方法硒化后均形成具有单一黄铜矿相结构的CuInSe2薄膜,薄膜具有(112)面择优取向,硒蒸气法形成的晶粒较大,但均匀性差。     

Properties of SnO2 films fabricated using a rectangular filtered vacuum arc plasma source

Transparent and conducting SnO₂ films of 57–200nm thickness were deposited on microscope glass slide substrates, using a rectangular filtered vacuum arc deposition system. The 40 glass slides were equally distributed on a 400 × 420mm substrate carriage, and were exposed to a Sn plasma beam, produced by a rectangular vacuum arc plasma gun with a Sn cathode, and passed through a rectangular magnetic macroparticle filter towards the substrates. The carriage with the substrates was transported past the 94 × 494mm filter outlet. The SnO₂ films were fabricated on the glass substrates at room temperature by maintaining the chamber oxygen background pressure at 0.52Pa. The film composition, and electrical and optical properties were studied as a function of the film thickness. The films were stored under ambient air conditions, and their electrical resistance was measured as a function of storage time over a period of several months.

The average resistivity of films was 10–17mΩ cm for films with thickness (t) less than 100nm, but that of t > 100nm it was 5–9mΩ cm. The resistivity of the films with t > 100nm did not change significantly after 8months of storage in ambient air. The optical transmittance of the films in the visible spectrum was in the range of 75–90%. The optical constants, i.e., the refractive index and the extinction coefficient of the films at wavelength λ = 550nm were in the range of 2.02–2.09 and 0.013–0.023, respectively, and the optical band gap energy was 4.15–4.21eV. Unlike the electrical resistivity, the optical parameters weakly depended on t.     

Structural, electrical and optical characteristics of SnO2:Sb thin films by ultrasonic spray pyrolysis

Antimony-doped tin oxide (SnO₂:Sb) thin films were fabricated by an ultrasonic spray pyrolysis method. The effect of antimony doping on the structural, electrical and optical properties of tin oxide thin films were investigated. Tin(II) chloride dehydrate (SnCl₂·2H₂O) and antimony(III) chloride (SbCl₃) were used as a host and a dopant precursor. X-ray diffraction analysis showed that the non-doped SnO₂ thin film had a preferred (211) orientation, but as the Sb-doping concentration increased, a preferred (200) orientation was observed. Scanning electron microscopy studies indicated that the polyhedron-like grains observed for the non-doped SnO₂ thin films became rounder and decreased in size with the Sb-doping concentration. The lowest resistivity (about 8.4 × 10^− 4 Ω·cm) was obtained for the 3 at.% Sb-doped films. Antimony-doping led to an increase in the carrier concentration and a decrease in Hall mobility. The transmittance level in the near infrared region was lowered with the Sb-doping concentration.     

Study of structural, electrical, optical, thermoelectric and photoconductive properties of S and Al co-doped SnO2 semiconductor thin films prepared by spray pyrolysis

In this paper, the effect of S and Al concentrations on the structural, electrical, optical, thermoelectric and photoconductive properties of the films was studied. The [Al]/[Sn] and [S]/[Sn] atomic ratios in the spray solutions were varied from 10 at.% to 40 at.% and 0 to 50 at.%, respectively. X-ray diffraction analysis showed the formation of SnO₂ cassiterite phase as a main phase and the numerous sulfur phases including S, SnS, SnS₂ and Sn₂S₃ in SnO₂:Al films. Scanning electron microscopy studies showed that in the absence of S, increasing the Al content results in a smaller grain size and with the addition of S, the films appear to contain small cracks and nodules. The minimum resistance of 0.175 (kΩ/□) was obtained for S-doped SnO₂:Al (40 at.%) film with 20 at.% S-doping. From the Hall effect measurements, the majority carrier concentration was obtained in order of 10¹⁷-10¹⁸ cm^− 3. The thermoelectric measurements showed that majority carriers change from electrons to holes for S-doping in SnO₂:Al (40 at.%) thin films. The maximum Seebeck coefficient of + 774 μV/K (at T = 370 K) was obtained for S-doped SnO₂:Al (10 at.%) film with 50 at.% S-doping. The band gap values were obtained in the range of 3.8-4.2 eV. The S-doped SnO₂:Al (40 at.%) films have shown considerably photoconductivity more than S-doped SnO₂:Al (10 at.%) with increasing S-doping. The best photoconductive property was obtained for co-doped SnO₂ thin film with 40 at.% Al and 5 at.% S concentration in solution.     

Effect of nitrogen partial pressure on the structure, physical and mechanical properties of CrB2 and Cr-B-N films

The investigation of structure and properties of Cr-B and Cr-B-N films deposited by direct current magnetron sputtering of CrB₂ target in argon and argon-nitrogen environments, respectively is presented. The nitrogen partial pressure was kept at 10, 15, and 25% of the total pressure. The microstructure, phase and chemical composition of Cr-B-(N) films were studied by means of X-ray diffraction, transmission- and scanning-electron microscopy, X-ray photoelectron spectroscopy, electron probe microanalysis and secondary neutral mass-spectrometry. The films were characterized in terms of their electrical resistivity, optical reflectivity and transmittance. Measurements of hardness and elastic modulus were performed by depth sensing nanoindentation. The results obtained show that the films deposited in pure Ar had a hexagonal AlB₂-type structure with crystallites, 15-17 nm in lateral size, elongated in the direction of film growth. The Cr-B-N films consisted of nanocrystalline nc-CrB₂ and amorphous a-BN phases. As the nitrogen content in films was raised, the volume fraction of the nc-CrB₂ phase decreased and a-BN phase increased. When nitrogen was added to the gas discharge during deposition, the nc-CrB₂ crystallite size decreased down to 3-5 nm. Without nitrogen, the films exhibited a columnar morphology. Nitrogen introduction suppressed the columnar growth of films because formation of a-BN intergranular layers. The films deposited under optimal parameters showed hardness in the range of 36-43 GPa and Young's modulus below 300 GPa. For all films, electrical resistivity values between approximately 200 and 700 µΩ cm were recorded.     

Dependence of La2O3 content on the nonlinear electrical behaviour of ZnO, CoO and Ta2O5 doped SnO2 varistors

The effects of La₂O₃ on the properties of (Zn, Co, Ta) doped SnO₂ varistors were investigated in this study. The samples with different La₂O₃ concentrations were sintered at 1400 °C for 2 h and their properties were characterized by XRD, SEM, I-V and impedance spectroscopy. The grain size was found to decrease from 13 μm to 9 μm with increasing La₂O₃ content. The addition of rare earth element leads to increase the nonlinear coefficient and the breakdown voltage. The enhancement was expected to arise from the possible segregation of lanthanide ion due to its larger ionic radius to the grain boundaries, thereby modifying its electrical characteristics. Furthermore, the dopants such as La may help in the adsorption of O′ to O″ at the grain boundaries characteristics.