ZnO/SnO2复合透明导电膜性能的研究

采用直流磁控溅射工艺在SnO:透明导电玻璃上沉积一层ZnO膜,制备出ZnO/SnO2复合透明导电膜,作为硅薄膜太阳电池前电极.比较了具有不同ZnO厚度的复合膜氢轰击前后的光电性能,发现适当控制ZnO膜的厚度至关重要.研究了快速热退火(RTA)对薄膜的结构及光电性能的影响,发现400℃退火能够改善薄膜的光学性能.     

透明导电薄膜与p-Si:H膜接触特性的研究

本实验采用PECVD方法在不同透明导电薄膜上沉积了p型掺杂(p-Si:H)膜.用拉曼(Raman)光谱测试了p-Si:H膜的晶化率,并用扫描电子显微镜(SEM)观察了其形貌.结果表明:在SnO2上沉积的p-Si:H膜的晶化率较其它两种衬底高,相应的SEM形貌显示颗粒尺寸也较大.通过I-V测试仪测试了ZnO:Al/p-Si:H、SnO2/p-Si:H和SnO2/ZnO:Al/p-Si:H的接触特性,结果显示ZnO:Al/p-Si:H的接触特性并不比SnO2/p-Si:H差.     

电阻蒸发铝薄膜结构及其对非晶硅太阳电池性能的影响

本文首先采用电阻蒸发法制备了不同厚度的Al薄膜,并选择了两个典型厚度的Al薄膜制备工艺来制备非晶硅太阳电池的Al背电极,研究了Al背电极厚度对电池性能的影响.结果表明,Al背电极的厚度由800nm减薄到70nm时,电池的Voc平均值由0.826V增加到0.829V,电池的Jsc平均值由11.747mA/cm2减小到11.318 mA/cm2,电池的FF平均值由0.701增加到0.728,而电池效率的平均值略有增加,由6.803;增加到6.833;.用扫描电镜(SEM)和X射线衍射(XRD)研究了玻璃衬底上蒸发的Al薄膜和非晶硅电池Al背电极表面形貌和微观结构的变化,分析了电池性能随Al背电极厚度变化的原因.     

ZnO/TiO2复合光阳极染料敏化太阳能电池的研究

采用醇热法制备ZnO纳米粉体,采用水热法制备TiO2纳米粉体,将不同质量分数的ZnO与TiO2混合制备浆料,采用刮涂法在掺氟的SnO2透明导电玻璃(FTO)上制备ZnO/TiO2纳米复合薄膜光阳极,与Pt对电极和电解质组装成染料敏化太阳能电池.采用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)和扫描电镜(SEM)对所制备的样品进行表征,通过光电性能测试和电化学阻抗谱测试,研究了添加不同质量分数的ZnO对电池性能的影响.结果表明:不添加ZnO纳米粉时,纯TiO2光阳极的电池光电转换效率为7.95;,而添加了2wt; ZnO的ZnO/TiO2复合光阳极电池的效率达到9.54;,比纯TiO2电池的效率提高了20;.     

绒面ZnO/Si异质结太阳能电池的初步研究

以p型单晶硅<100>作为衬底材料,通过化学腐蚀法得到硅绒面表面结构,采用喷雾热解法沉积掺Al的ZnO薄膜于绒面硅上,结合微电子光刻、磁控溅射和真空蒸镀等工艺制作上、下表面电极,于400 ℃氮气氛围下快速退火合金,得到Ag/Ti/n-ZnO/p-Si/Al异质结太阳能电池.对电池样品进行了原子力显微镜、霍尔效应测试、X射线衍射谱、电流电压特性等分析.得到电池最佳性能为:开路电压V_(oc)=355 mV,短路电流I_(sc)=36 mA,填充因子FF=0.41,电池效率达到5.2;.绒面异质结构有效降低了电池表面的光反射,相对增加了p-n结的有效面积,电池效率得到一定程度的提高.ZnO与Si界面之间SiO_2层的存在是目前影响电池效率的主要因素.     

GZO/Al复合背电极对非晶硅太阳能电池的影响

随着能源紧缺与环境污染问题的日益严重,太阳能的开发利用越来越受到重视,其中非晶硅薄膜太阳能电池由于其制备工艺简单、价格低廉等优点被广泛地研究.为了使非晶硅薄膜太阳能电池得到更好地利用,提高其转换效率和稳定性显得尤为重要.引入复合背电极是提高非晶硅太阳能电池性能的有效手段,其中对GZO/Al复合背电极的研究还未见报道.在该工作中,利用磁控溅射法在非晶硅电池上制备了GZO/Al复合背电极,研究了复合背电极的制备条件及其对非晶硅太阳能电池性能的影响.结果显示,当GZO层的溅射功率为90 W、Al层的溅射功率为90 W时,具有复合背电极的太阳能电池表现出较好的光电转换性能,其短路电流(ISC)、开路电压(VOC)、填充因子(FF)和电池的光电转换效率(η)分别为8.92 mA、1.55 V、54.48;和7.53;.相较于单层Al背电极的太阳能电池,其光电转换效率大幅提高了47.6;(相对效率).     

三种改性方法对纳米ZnO催化剂粉体的光催化性能的影响

以SnCl4·5H2O、ZnNO3·6H2O、HCl、NaOH、FeCl3·6H2O为原料,采用共沉淀法制备Fe掺杂纳米ZnO、纳米ZnO/SnO2和Fe掺杂纳米ZnO/SnO2三种复合催化剂粉体,以降解甲基橙溶液反应为模型,研究了不同比例的ZnO/SnO2复合、Fe元素掺杂量以及SnO2复合Fe元素掺杂同时作用对纳米ZnO粉体光催化活性的影响,采用X射线衍射(XRD)测试方法对不同量Fe元素掺杂纳米ZnO粉体进行了表征.采用透射电镜对三种改性方法ZnO粉体进行表征.结果表明:随着ZnO/SnO2的物质的量比增加,ZnO/SnO2复合光催化剂的催化活性先增加,然后降低;随着Fe掺杂量的增加,纳米ZnO粉体的光催化活性先增加,然后降低.三种改性方法都能提高纳米ZnO粉体的光催化活性,其中Fe元素掺杂以及SnO2复合改性纳米ZnO粉体的光催化效果最好,物相为ZnO和SnO2,颗粒尺寸为15 ～20 nm,分散性好,比表面积为68.7m2/g.     

反应磁控溅射制备AZO薄膜相结构的演化及机理研究

在室温下,利用直流反应磁控溅射技术在不同的氧气流量下沉积ZnO∶ Al (AZO)薄膜.采用XRD、SEM和TEM技术分析薄膜相成分、表面截面形貌及微观结构.结果表明:氧气流量为2.5 sccm时,沉积形成的薄膜为不透明具有金属导电性能的AZO/Zn( AZO)双层复合膜结构;氧气流量为3.5 sccm时,沉积形成了透明导电的AZO薄膜;氧气流量为5.0 sccm时,形成了透明不导电且含有纳米Al2O3颗粒的AZO薄膜;此外,AZO薄膜在400℃退火后,薄膜晶粒长大和(002)晶面方向择优生长更加明显以及高氧气流量沉积的AZO薄膜中的纳米Al2O3颗粒消失.     

P型ZnO薄膜的制备及其在太阳电池中的初步应用

利用超声雾化热分解技术(USP)、通过N-Al共掺的方法,在coming 7059衬底上生长出P型透明导电膜.该薄膜在可见光范围内的透过率可达到90;以上.X射线衍射的测试结果表明:P型透明导电膜具有c轴择优生长特性.通过霍耳测试得到P型ZnO薄膜的电学特性为:电阻率为4.21 Ω·cm、迁移率是0.22 cm2/(V·s)、载流子浓度为6.68×1018cm-3.此材料初步应用到微晶硅电池中,其开路电压为0.47 V.     

衬底对宽带隙CGS薄膜的影响

分别在Al∶ ZnO(ZAO)薄膜和Mo薄膜两种不同衬底材料上,采用“三步法”共蒸发工艺沉积了约0.8 μm厚的CuGaSe2(CGS)薄膜,用X射线衍射仪测量薄膜的织构,研究不同衬底材料对CGS薄膜的影响.在ZAO薄膜底电极上沉积的CGS薄膜的(112)衍射峰强度较Mo薄膜底电极上减弱,(220/204)衍射峰反而增强.     

A review of measurement of thermophysical properties of silicon melt

Measurements of thermophysical properties of Si melt and supplementary study of X-ray scattering/diffraction by the authors' group were reviewed. The values obtained differed variously from those of literature. Density was 2–3% larger, surface tension 20–30% smaller, viscosity up to 40% larger, electrical conductivity 8% smaller, spectral emissivity more or less in good agreement with literature values, and thermal diffusivity a few percent larger. An anomalous density jump was found near the melting point. Surface tension and viscosity also showed anomaly. A strange time-dependent change of density was observed over 3 h after melting. X-ray analyses suggested a slight change in local atom ordering, but showed no sign of cluster formation. An addition of 0.1 at% gallium caused the density jump to disappear, while that of boron caused no change. An EXAFS study of the former melt indicated a strong interaction between Ga and Si atoms as if molecules of GaSi₃ existed. The implications of the measured properties are a possibility of soft-turbulence in an Si melt in a relatively large crucible, a more complicated manner of intake of oxygen depleted molten Si from the free surface region to underneath the growing crystal, and a relaxation of the melt after melting arising from trapped gas species.     

Mesomorphism Dependence on the Position of Substitution of a Pair of Esters

A novel homologous series of ethylene derivatives of thermotropic liquid crystals has been synthesized. The methoxy to octyloxy derivatives are nematogenic, the decyloxy to tetradecyloxy derivatives are smectogenic, in addition to nematogenic, and the hexadecyloxy homologue is smectogenic only. All the members of the series are enantiotropically mesogenic. Thermotropic behavior was determined by an optical polarizing microscope equipped with a heating stage and Differential Scanning Calorimetry (DSC) study. Analytical and spectral data confirm the molecular structures of homologues (infrared, nuclear magnetic resonance, mass spectra, X-ray, and DSC data). Textures of the nematic phase are threaded or Schlieren and that of smectic phase are focal conic fan-shaped of smectic A or C. Transition curves of the phase diagram behave in a normal manner except one or two deviations from the normal trend. The mesophase range (Sm+N) varies from 3°C to 44°C. The average thermal stability for smectic is 93°C and that for nematic 117.4°C. The LC behavior of the novel series is compared with a structurally similar known series.     

Effect of alumina on enthalpy of mixing of mixed alkali silicate glasses

The enthalpy of mixing of mixed alkali (Na₂O and K₂O) silicate glasses containing various concentrations of alumina was determined using an ion-exchange equilibrium method. For glasses with a constant alkali concentration, the enthalpy of mixing was found to become less negative with alumina addition. Consistent with our previous results on the enthalpy of mixing of alumina-free mixed alkali silicate glasses, the magnitude of enthalpy of mixing exhibited a good correlation with the molar volume mismatch of the corresponding two single alkali glasses as well as with the extent of conductivity mixed alkali effect, e.g. excess activation energy of conductivity, ΔE. The reduction of the magnitude of the enthalpy of mixing with alumina addition can be attributed to the reduction of non-bridging oxygen and ionic field strength. Combining the present results with results obtained earlier, the magnitude of the enthalpy of mixing for all mixed alkali (Na₂O and K₂O) silicate glasses with and without alumina was expressed by a simple function of a modified Tobolsky parameter, which takes into account the alkali concentration and the difference in cation-to-effective anion distances. The enthalpy of mixing data of the mixed alkali glasses was then compared with reported experimental data on the conductivity of mixed alkali aluminosilicate glasses. What appears to be conflicting experimental data can be understood in terms of the magnitude of the enthalpy of mixing and we can conclude that the mixed alkali effect is closely correlated with the negative enthalpy of mixing.     

电子显微分析在表征纳米晶体化学组分中的应用

纳米材料的化学组分及含量影响其光、电、声、热、磁等物理性能,电子显微分析是表征纳米晶体化学组分的重要方法之一.本文综述了X-射线能谱(EDS)、X-射线波谱(WDS)、电子能量损失谱(EELS)和选区电子衍射(SAED)等现代电子显微分析技术在表征纳米晶体化学组分、形貌、尺寸和结构等方面的应用及其研究进展,并比较了这些分析方法存在的差异,提出了其应用中存在的不足及今后的研发方向.     

On the influence of structural features of DNA on the possibility of metabolic transfer of electrons

Abstract

A fragment of a DNA molecule is considered as one of the channels of metabolic electron transfer. The heterogeneity of the complementary chains is effectively taken into account. This made it possible to find the speed of the electron injected into the DNA conduction band and the current density that it creates. Estimates of electron mobility in nucleic acid chains are made. They were an order of magnitude smaller than that of typical semiconductors. For the specific conductivity of nucleic acid chains, estimates provide a conductivity of one to two orders of magnitude lower than in graphite.     

原位氮化法制备TiN纳米粉体

用溶胶凝胶法合成的纳米TiO2粉体作为原料,将该粉体在氨气中进行原位氮化制备了TiN纳米粉体.用XRD,TEM,化学分析等手段对合成的TiN纳米粉体的物相组成、形貌、成分进行了分析.实验分析表明:在1000℃和1100℃下分别氮化5h,可以制备粒径大约为40nm和80nm的TiN粉体,其TiN的含量分别为95.40;和98.37;;而在1000℃条件下氮化时间减少到2h时,TiN的含量仅为58.36;.氮化温度和氮化时间是合成纳米TiN的重要因素,提高合成温度和延长氮化时间均可形成纯度较高的TiN纳米粉体,但延长氮化时间更有利于获得粒径小的氮化钛粉体.     

立方晶系晶体本征铁弹相变序参量的选取

在本征铁弹相变的软模理论的基础上,依据弹性本构关系和居里原理,给出了立方晶系晶体所有可能的自发应变的种类,研究了立方晶系晶体本征铁弹相变序参量的选取问题.以Th群和Oh群为例,阐明了不同类的序参量导致晶体对称性变化相同的的原因,提出了该情况下序参量选取的“就少不就多”的原则.得到了发生本征铁弹相变时所有可能的序参量及晶体的对称性的变化.     

Features of transformations in REE-containing systems of nitrate precursors in preparatory processes of formation of multifunctional oxide materials

Abstract

The complex study provides a reliable idea of ??the trends in the joint behavior of structural components in the water-salt systems of nitrate precursors of REE, alkaline, alkaline earth metals in the preparatory stages of the processes of forming multicomponent oxide polyfunctional materials on their basis with thermal activation. Stages of such transformations are revealed; The regularities of complex and phase formation in systems and factors influencing them are determined; A number of physicochemical properties of the intermediate phases formed - coordination lanthanides nitrates: their composition, types of compounds, atomic-crystalline structure, regularities of transformations during heat treatment were studied.     

Growth and characterization of semicarbazone of cyclohexanone

A new organic single crystal of semicarbazone of cyclohexanone (SCCH) has been synthesized and grown as a bulk single crystal by low temperature solution growth technique for the first time in the literature. The grown crystal has been confirmed by X‐ray diffraction and proton nuclear magnetic resonance spectral analyses and also characterized by FT‐ir and FT‐Raman studies. Thermal properties of the grown crystals were studied by thermogravimetric and differential thermal analyses. Optical transmittance was studied by ultraviolet‐visible spectrum and the second harmonic generation property was tested by using Q switched Nd: YAG laser as a source. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

PEG聚合度对氧化铝造粒粉的性能影响

为制备适用于干压成型的氧化铝造粒粉,研究了PEG聚合度对氧化铝造粒粉微观形貌、流动性和松装密度的影响.结果表明PEG的聚合度对氧化铝浆料粘度影响显著,PEG2000-6000是较为理想的粘结剂选择,造粒粉的流动性与环境温度及湿度相关.采用正交实验设计,以造粒粉的流动性和松装密度为评价指标,对PEG聚合度、粘结剂添加量和固含量进行了优选,其影响顺序为PEG聚合度＞固含量＞粘结剂添加量.以优选参数PEG6000、添加量为4wt;、固含量为80wt;,制备了性能优良的氧化铝喷雾造粒粉.