不同方法制备的C60材料的发光行为

采用Ｓｏｌ－Ｇｅｌ溶胶－凝胶的方法出了掺杂Ｃ６０的Ｎａ２Ｏ－Ｂ２Ｏ３－ＳｉＯ２干凝胶和掺杂Ｃ６０的ＳｉＯ２ＰＤＭＳ（聚二甲基硅氧烷）的凝胶材料。测量了纯Ｃ６０粉的吸收光谱和掺杂Ｃ６０偻的凝胶材料在不同温度下的发射光谱。观测到了Ｃ６０／ＮＢＳ在３０Ｋ～２００Ｋ温度范围Ｃ６０的发光峰位于１．６９ｅＶ,发光峰随着温度的升高向低能边有一较小偏移,并且谱峰强度减弱。对实验数据进行了拟合。分析了发光与温度的关     

键合Si／SiO_2／Si结构的C－V特征

本文研究了理想Ｓｉ／ＳｉＯ２／Ｓｉ结构的电容－电压（Ｃ－Ｖ）特征，提出了根据Ｓｉ／ＳｉＯ２／Ｓｉ的Ｃ－Ｖ特征测量ＳｉＯ２厚度、衬底掺杂浓度和固定电荷的方法，并对键合样品进行了实验．     

键合Si／SiO2／Si结构的C—V特征

本文研究了理想Ｓｉ／ＳｉＯ２／Ｓｉ结构的电容－电压（Ｃ－Ｖ）特性，提出了根据Ｓｉ／ＳｉＯ２／Ｓｉ的Ｃ－Ｖ特征测量ＳｉＯ２厚度、衬底掺杂浓度和固定电荷的方法，并对键合样品进行了实验。     

硫化镉纳米微晶掺杂Na2O—B2O3—SiO2系统玻璃的制备及光学性质 …

本文采用Ｓｏｌ－ｇｅｌ方法制备了掺杂ＣｄＳ纳米微晶的Ｎａ２Ｏ－Ｂ２Ｏ３－ＳｉＯ２系统玻璃,研究了这种玻璃材料的合成反应机理和结构特性。利用各种温度下玻璃中掺杂纳米尺寸ＣｄＳ半导体微晶的光致发光光谱,研究了其光致发光带的峰值能量和线宽对温度的信赖关系,拟合了其带隙发光带的线宽随温度的变化曲线,获得样品的非均匀线宽。ＣｄＳ微晶的非均匀线宽主要是由于微晶的尺寸分布引起的,可以利用ＣｄＳ微晶的非均匀宽化系     

CdS微晶掺杂TiO2—SiO2复合薄膜的非线性光学特性

采用溶胶－凝胶方法在普通的载玻片上制备了ＣｄＳ微晶掺杂的ＴｉＯ２－ＳｉＯ２复合薄膜。用正硅酸乙酯、钛酸丁酯、醋酸镉作原料，比较了硫脲和硫化乙氨的硫化作用。不同热处理温度、时间的吸收光谱表明，薄膜中存在着量子尺寸效应。采用Ｚ－Ｓｃａｎ技术测量了薄膜的非线性吸收及非线性折射率。     

Au掺杂TiO2／SiO2薄膜的光学非线性特性研究

采用溶胶－凝胶方法制备了Ａｕ掺杂的ＴｉＯ２／ＳｉＯ２复合薄膜（厚度约为１．０μｍ）。Ｘ－ｒａｙ衍射分析表明，Ａｕ的颗粒镶嵌在ＴｉＯ２／ＳｉＯ２复合薄膜的玻璃网络中。谢乐公式计算给出Ａｕ的颗粒大小约为１０ｎｍ。采用Ｚ－Ｓｃａｎ测量技术得此薄膜的光学非线性折射率为１．０９×１０－７ｅｓｕ。     

SiO2对SnO2.CoO.Nb2O5压敏电阻非线性电学性质的影响

对ＳｉＯ２掺杂的ＳｎＯ２．ＣｏＯ．Ｎｂ２Ｏ５压敏电阻非线性电学性质进行了研究,并对其微观结构进行了电镜扫描,且对其晶界势垒高度进行了测量,实验表明ｘ（ＳｉＯ２）＝０．３％掺杂的ＳｎＯ．ＣｏＯ．Ｎｂ２Ｏ５压敏电阻的非线性系数ａ高达３０,并且具有最高的击穿电场（３７５Ｖ／ｍｍ）。采用Ｇｕｐｔａ－Ｃａｒｌｓｏｎ缺陷模型对晶界肖特基势垒高度随ＳｉＯ２的添加而变大的现象进行了理论解释。     

气敏器件用SnO_2薄膜材料

采用溶胶－凝胶法以ＳｎＣｌ２·Ｈ２Ｏ和ＺｒＯＣｌ２·８Ｈ２Ｏ为原料,制备出性能优良的纳米ＳｎＯ２薄膜材料。用Ｘ射线衍射仪分析了晶相,ＴＥＭ分析了微观结构。研究了掺杂、处理温度等对其性能的影响。在此基础上制作了ＳｎＯ２薄膜气敏器件,并检测了其气敏特性。     

激光烧蚀掺杂氧化硅气凝胶产生SiO_2团簇的实验研究

利用飞行时间质谱方法．研究了多种掺杂氧化硅气凝胶在激光作用下在负离子通道中的团簇形成特性．测得几个主要的ＳｉＯ２团簇系列．讨论了掺杂物在激光能量吸收及传输与团簇产生机理中的重要作用。     

SrS：Ce蓝色薄膜电致发光

用Ｈ２还原法制备了ＳｒＳ：Ｃｅ蓝色发光材料，研究了它的光谱特性，并用不同掺杂浓度比较了Ｈ２还原法和ＣＳ２还原法，得到了掺杂的浓度范围，研究了Ｈ２气氛下处理温度对器件发光的影响。制得了最高亮度为２２０ｃｄ／ｍ＾２，流明效率为０．１８１ｍ／Ｗ的蓝色发光器件。     

掺Pb的TiO2纳米功能材料的制备及其光催化性能

采用溶胶－凝胶法制备了掺Pb的摩尔比分别为0.5%、1%、3%、5%、7%、10%的改性TiO2纳米粒子，并利用XRD和UV－VIS检测技术对所制得的样品进行了表征，考察了焙烧温度和掺Pb量对材料组成、结构和光学性质的影响；另外，以模拟太阳光下苯酚的光催化降解为模型反应，对Pb改性的TiO2纳米粒子的光催化活性进行了评价，考察了掺Pb量对材料催化性能的影响。结果表明，掺入适量的Pb后，TiO2纳米粒子的光催化活 性得到较大的提高，这可能是由于Pb进入TiO2晶格中生长成了新相PbxTi1-xO2，从而使材料的光响应范围向可见光区移动，提高了对可见光的利用率。本实验表明，掺Pb的摩尔比为3％的改性TiO2纳米粒子的光催化活性最高。     

铜掺杂多孔硅的光致发光及其载流子的复合过程

采用浸泡镀敷的方法在多孔硅表面形成了一镀铜层,通过对掺铜前后多孔硅的光致发光(PL)谱和傅里叶变换红外(FTIR)吸收光谱的研究,讨论了铜在多孔硅表面的吸附对其光致发光的影响。实验表明,掺铜多孔硅的光致发光谱出现两个发光带,其中能量较低的发光带随主发光带变化,并使多孔硅的发光峰位蓝移。多孔硅发光峰位的蓝移,是由于在发生金属淀积的同时伴随着多孔硅表面Si的氧化过程(纳米Si氧化为SiO2)的缘故。     

稀土氧化物掺杂对Ba0.6Sr0.4TiO3-MgO复合物结构及微波介电性能的影响

研究了不同质量分数(0~1.5%)的各种稀土氧化物对Ba0.6Sr0.4TiO3(40%)-MgO(60%)陶瓷微观结构和介电性能的影响.研究表明,大半径的稀土离子掺杂能有效降低材料的介电常数并提高品质因数;而小半径的稀土离子掺杂则会提高材料的微波介电损耗.当掺杂量超过0.2%时,所有样品的调谐率都随着添加量的增加而下降.与未掺杂的BST-MgO相比,0.2%稀土掺杂样品的调谐率变化规律及机理随掺杂物的不同而不同:Nd2O3和Yb2O3 掺杂样品中调谐率的大幅度升高归因于结电容的贡献,Sm2O3 掺杂样品调谐率的下降主要由MgO晶粒的聚集所致,而Y3+同时占据A位和B位引起了样品调谐率的下降.研究发现在BST-MgO中添加具有大离子半径的稀土氧化物(如La2O3、CeO2、Nd2O3、Sm2O3)并优化其添加量,能满足铁电移相器等微波调谐器件的要求.     

Al掺杂对ZnO薄膜形貌和光学性能的影响

采用溶胶-凝胶旋涂法在FTO玻璃衬底上制备得到了不同Al掺杂浓度的ZnO薄膜(AZO)。利用XRD、FESEM、UV-vis和PL等测试手段对样品结构、形貌和光学性能进行了表征。结果表明,合成的AZO薄膜均为六方纤锌矿结构且峰强随掺杂浓度的升高而减弱;同时,颗粒形貌由不规则向规则球形转变且尺寸逐渐减小;PL谱中的近紫外发射峰和晶格缺陷峰值随掺杂浓度的升高先增大后降低;由UV-vis吸收光谱可知,AZO薄膜在设定波长内的光吸收处于波动状态,且当Al掺杂浓度为3%时,光吸收强度最高,禁带宽度减小到3.12eV。     

Synthesis and photoluminescence characterizations of the Er3+-doped ZnO nanosheets with irregular porous microstructure

Er-doped ZnO nanosheets with high quality were synthesized by the hydrothermal and post-annealing techniques, and the effect of erbium dopant on the structures, morphologies and photoluminescence properties of the as-synthesized samples were determined using XRD, SEM, TEM, EDS, PL and Raman spectroscopy. The results showed that Er³⁺ ions were successfully incorporated into the crystal lattice of ZnO host, and some irregular porous microstructure with diameter of 3–10 nm could be seen on ZnO nanosheets as various doping concentrations. It was found that the crystallization and photoluminescence properties of ZnO nanosheets were strongly influenced by erbium doping concentration. The ultraviolet emission and deep level emission were both appeared in PL spectra, and the intensity of the whole deep level emission was enhanced with erbium doping, indicating the deep-level-defect luminescent centers were increased in the doped samples. Moreover, the crystallization of the samples became worse due to more defects by erbium doping.     

Solid state synthesis of erbium doped ZnO with excellent photocatalytic activity and enhanced visible light emission

The doped ZnO crystals with different erbium content were prepared by solid state reaction technique. The method is simple, relatively less expense and enables the production in large scale. The samples were characterised by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV/vis diffuse reflectance spectroscopy and photoluminescence techniques. Photocatalytic activity of samples was investigated by the degradation of methylene blue under UV light irradiation and was observed that, small fractions of erbium incorporation have a significant role in the enhancement of photocatalytic activity of ZnO. And the good stability of prepared catalysts makes them suitable for practical applications. Fluorescent property studies of erbium doped ZnO at room temperature show enhanced visible light emission due to the production of induced defects like antisite oxygen O_Zn and interstitial oxygen O_i. This work reports the co-existence of two mutually exclusive properties such as fluorescence and photocatalytic activity at their best in 0.6 wt% erbium doped ZnO.     

Band-Like Charge Transport in Phytic Acid-Doped Polyaniline Thin Films

We explore the charge transport properties of phytic acid (PA) doped polyaniline thin films prepared by the surfactant monolayer-assisted interfacial synthesis (SMAIS). Structural and elemental analysis confirms the inclusion of PA in the thin films and reveals a progressive loss of crystallinity with the increase of PA doping content. Charge transport properties are interrogated by time-resolved terahertz (THz) spectroscopy. Notably, independently of doping content and hence crystallinity, the frequency-resolved complex conductivity spectra in the THz region can be properly described by the Drude model, demonstrating band-like charge transport in the samples and state-of-the-art charge carrier mobilities of ≈1 cm²V⁻¹s⁻¹. A temperature-dependent analysis for the conductivity further supports band-like charge transport and suggest that charge carrier mobility is primarily limited by impurity scattering. This work highlights the potential of PA doped polyaniline for organic electronics.     

Enhanced photo-degradation methyl orange by N–F co-doped BiVO4 synthesized by sol–gel method

Using ammonium fluoride (NH₄F) as the source of nitrogen (N) and fluorine (F), N–F co-doped bismuth vanadate (BiVO₄) visible-light-driven photocatalysts have been synthesized via a sol–gel method. The resulting materials were characterized by a series of techniques: X-ray photoelectron spectroscopy, X-ray diffractometry, scanning electron microscopy, Brunauer–Emmett–Teller (BET) surface analysis, and UV–vis diffuse reflectance spectroscopy. Compared with BiVO₄, the N–F co-doped BiVO₄ photocatalysts exhibited much higher photocatalytic activity for methyl orange (MO) degradation under visible light irradiation. It was revealed that N and F atoms were doped into the lattice of BiVO₄. The doped N atoms existed as O–N or V–O–N bonding, and the F atoms replaced some O atoms to form the O–V–F structure, which can be attributed to the appearance of more active species V⁴⁺ and oxygen vacancies. The doped N and F atoms resulted in a red shift in the absorption edge. However, the N and F doping only slightly changed the morphologies and BET special surface areas of the samples. The photocatalytic activity of BiVO₄ significantly depended on the N–F doping content and the calcination temperature. The maximum activity was observed for the catalyst obtained with calcination at 500 °C, a molar ratio of NH₄F to Bi(NO₃)₃ was 6%.     

Reactive pulsed laser deposited N–C codoped TiO2 thin films

TiO₂ is a large bandgap chemically stable oxide useful for several applications that involve photo-activated processes, including photocatalysis, photovoltaics, photoelectrolysis, etc. However, the large band gap renders this material not a very efficient absorber of the solar spectrum. Various schemes of cation and anion doping have been utilized that reduce this deficiency to a certain extent. In this paper we present the results of N–C codoping of TiO₂ thin films deposited by a reactive pulsed laser deposition technique. These films were compared for their optical and structural properties with undoped, N doped and C doped TiO₂ films prepared by the same technique. While all samples contained polycrystalline anatase phase, varying N₂ and CH₄ partial pressures resulted in change in TiO₂ lattice parameters due to codoping. X-ray diffraction high-resolution scans show the evidence of C incorporation into TiO₂ lattice by 2θ shift in (101) reflections due to large ionic radius of C. N doping was confirmed by XPS analyses. Direct relationship between oxygen vacancies and doping concentration was established by the deconvolution of XPS peaks. Considerable bandgap reduction occurred that was measured by using UV–vis diffuse reflectance spectroscopy. Results show that reactive pulsed laser deposition is indeed a useful method for the synthesis of codoped TiO₂ thin films as bandgap reduction of ~1.00 eV via N–C codoping was successfully achieved.     

The effects of Al doping and post-annealing via intrinsic defects on photoluminescence properties of ZnO:Eu nanosheets

Europium (Eu) and Aluminum (Al) co-doped ZnO nanosheets were synthesized by a hydrothermal method. The effects of Al concentration as a dopant and post-annealing of ZnO:Eu nanosheets on its structural, electrical and optical properties were investigated in detail. Prepared samples were characterized structurally using X-ray diffraction (XRD), morphologically using scanning electron microscopy (SEM) and optically using photoluminescence (PL) spectroscopy analyses. No diffraction peak related to dopants in XRD spectrum along with shift in peaks angles relevant to ZnO proved that Al and Eu ions were doped successfully into ZnO nanosheets. This study recommends that extrinsic doping and intrinsic defects have impressive roles on transferring energy to Eu ions at indirect excitations. Based on photoluminescence observations, intra-4f transitions of Eu³⁺ ions at an excitation wavelength of 390 nm allow a sharp red luminescence. Also the results showed that optical properties of ZnO can be tuned by varying the amount of Al concentration. In comparison with annealed Al doped ZnO:Eu nanostructures, as-grown samples showed the stronger PL peaks which indicated the effective role of intrinsic defects beside of extrinsic doping on energy transfer from ZnO host to Eu³⁺ ions which consequently led to producing the strong red emission from these sites.