纳米TiO2∶Zn薄膜电极紫外光电特性研究

采用sol-gel法制备了Zn2+掺杂的锐钛矿相纳米TiO2薄膜电极.通过光电流作用谱和电流-电位（I-U）曲线研〖WTBZ〗究了掺杂不同浓度Zn2+的TiO2薄膜电极的光电特性.由光电流作用谱可知，Zn2+的掺杂可显著影响薄膜电极的光电流大小，且掺杂的最佳浓度与薄膜晶粒尺度有关.在320nm单色光照射下，掺杂浓度（摩尔浓度）为0.1％的薄膜电极光电流最大，与未掺杂的本征薄膜电极相比增幅达40％.I-U曲线表明，光照下，随电极电位由正到负逐渐降低，不同掺杂浓度的TiO2薄膜电极中均出现了阳极电流向阴极电流转换的现象，且Zn2+掺杂浓度可影响电极阳极电流的初始电位.另外，无光照的暗态下，各薄膜在负电位区域观察到了相似的随电位降低而迅速增大的阴极暗电流.     

纳米TiO_2∶Zn薄膜电极紫外光电特性研究

采用sol-gel法制备了Zn2 掺杂的锐钛矿相纳米TiO2薄膜电极.通过光电流作用谱和电流-电位(I-U)曲线研究了掺杂不同浓度Zn2 的TiO2薄膜电极的光电特性.由光电流作用谱可知,Zn2 的掺杂可显著影响薄膜电极的光电流大小,且掺杂的最佳浓度与薄膜晶粒尺度有关.在320nm单色光照射下,掺杂浓度(摩尔浓度)为0.1%的薄膜电极光电流最大,与未掺杂的本征薄膜电极相比增幅达40%.I-U曲线表明,光照下,随电极电位由正到负逐渐降低,不同掺杂浓度的TiO2薄膜电极中均出现了阳极电流向阴极电流转换的现象,且Zn2 掺杂浓度可影响电极阳极电流的初始电位.另外,无光照的暗态下,各薄膜在负电位区域观察到了相似的随电位降低而迅速增大的阴极暗电流.     

多孔TiO2/Al/SiO2纳米复合结构的紫外光吸收特性研究

在SiO2玻璃衬底上用脉冲激光沉积(PLD)技术,分别沉积Ti和Ti/Al膜,经电化学阳极氧化成功制备了多孔TiO2/SiO2和TiO2/Al/SiO2纳米复合结构.其中TiO2薄膜上的微孔阵列高度有序,分布均匀.实验研究了Al过渡层对多孔 TiO2薄膜光吸收特性的影响.结果表明:无Al过渡层的多孔 TiO2薄膜其紫外吸收峰在270 nm处.且峰强不随阳极氧化工艺参数调节;而有Al过渡层的多孔TiO2薄膜其紫外吸收峰红移至293 nm处,峰强和峰形不仅受阳极氧化电压调节而且受Al过渡层厚度的影响也很敏感.进一步分析了两种结构在吸收边附近的光跃迁特性.这些结果对基于多孔 TiO2的光伏电池和紫外光传感器的应用研究非常有益.     

表面修饰纳米TiO2的贮氢合金电极的光充电行为

采用水解-沉淀法制备了锐钛矿结构的纳米级TiO2,研究了表面修饰TiO2的贮氢合金电极的光充电、循环伏安及交流阻抗特性.结果表明,表面未修饰TiO2的贮氢合金电极在光照下电极电位基本无变化,而表面修饰TiO2的贮氢合金电极在光照下,电极电位向负方向偏移,可达-0.835V,表明在光照射条件下电极表面有氢原子形成.电化学阻抗谱的结果也表明,表面修饰电极在光照时表面有吸附氢存在,并存在氢原子向贮氢合金内部的扩散过程.扫描电镜观察表明,表面修饰TiO2的贮氢合金电极在光充电后产生的氢原子被贮氢合金吸收引起膨胀,导致表面出现大量微裂纹.     

TiO_2/Sm~(3+)下转换薄膜的制备及其在染料敏化太阳能电池中的应用

采用溶胶-凝胶法制备了TiO2/Sm3+下转换薄膜,利用其下转换特性将紫外光转换为可见光,提高了可见光光照强度。利用X射线衍射和荧光光谱对TiO2/Sm3+粉体进行了表征,并对TiO2/Sm3+下转换薄膜进行了荧光光谱测试和紫外-可见分光光度计测试。荧光光谱显示,TiO2/Sm3+薄膜在受到395 nm紫外光照射时可发射出540~600 nm连续波长的可见光,具有下转换特性。二层TiO2/Sm3+下转换薄膜的可见光透过率与单纯的TiO2薄膜基本相同,利用其下转换特性使电池短路电流提高了13.2%,光电转换率提高了16.2%。     

TiO_2/Eu~(3+),Y~(3+)下转换薄膜的制备及其在染料敏化太阳能电池中的应用

采用溶胶-凝胶法制备了TiO2/Eu3+,Y3+下转换薄膜,将其应用到染料敏化太阳能电池中,利用其下转换特性将紫外光转换为可见光,提高了电池的可见光照强度.利用X射线衍射和荧光光谱对TiO2/Eu3+,Y3+粉体进行表征,利用荧光光谱和紫外-可见分光光度计对TiO2/Eu3+,Y3+下转换薄膜进行测试,荧光光谱显示,下转换薄膜受到396nm紫外光照射时可发射出535~620nm连续波长的可见光,具有下转换功能特性.与TiO2薄膜相比,二层下转换薄膜仍能保持较高的可见光透过率.当稀土元素总掺量为4%时,利用下转换特性使短路电流提高了21.5%,光电转换效率提高了14.1%.     

纳米二氧化钛的制备及Eu~(3+)掺杂发光研究

以钛酸四丁酯为前驱物,采用溶胶-凝胶法制备了四种不同配方Eu3+掺杂的TiO2纳米晶.利用扫描电镜(SEM)、EDS能谱、光致发光光谱对样品的形貌、成份及性能进行了表征.研究了退火温度、稀土Eu3+离子掺杂摩尔分数、溶剂乙醇量等对发光性能的影响,并对其发光机理进行了探讨.结果表明:稀土Eu3+掺杂TiO2纳米晶样品,掺杂均匀、颗粒大约在30～80nm;从EDS能谱分析可得Ti:O原子个数比并不是按化学计量TiO2满足1:2,这是因为在TiO2中形成的是Ti-O-Ti键,Eu3+离子很可能取代了Ti4+离子,同时又形成了氧空位,表明稀土Eu3+离子进入TiO2晶格中;样品的主发射峰在614nm(5D0→7F2)处发光最强,且在593nm(5D0→7F1)处出现了属于磁偶极跃迁的发射峰,制备Eu3+∶TiO2纳米晶的组分、退火温度、溶剂乙醇的量不同,发射光谱的强度也不同.     

纳米二氧化钛的制备及Eu3＋掺杂发光研究

以钛酸四丁酯为前驱物,采用溶胶-凝胶法制备了四种不同配方Eu3+掺杂的TiO2纳米晶.利用扫描电镜（SEM)、EDS能谱、光致发光光谱对样品的形貌、成份及性能进行了表征.研究了退火温度、稀土Eu3+离子掺杂摩尔分数、溶剂乙醇量等对发光性能的影响,并对其发光机理进行了探讨.结果表明:稀土Eu3+掺杂TiO2纳米晶样品,掺杂均匀、颗粒大约在30~80 nm|从EDS能谱分析可得Ti:O原子个数比并不是按化学计量TiO2满足1:2,这是因为在TiO2中形成的是Ti-O-Ti键,Eu3+离子很可能取代了Ti4+离子,同时又形成了氧空位,表明稀土Eu3+离子进入TiO2晶格中|样品的主发射峰在614 nm(5D0→7F2)处发光最强,且在593 nm(5D0→7F1)处出现了属于磁偶极跃迁的发射峰,制备Eu3+∶TiO2纳米晶的组分、退火温度、溶剂乙醇的量不同,发射光谱的强度也不同.     

Sb掺杂纳米TiO2光催化剂的晶体结构与光催化性能

用溶胶-凝胶法将纳米TiO2:Sb薄膜沉积在玻璃基板上．通过XRD、Raman光谱研究了Sb掺杂量对薄膜的晶体结构和晶相转变的影响．结果表明:纯TiO2薄膜中,TiO2不仅以无定型态存在,而且还以板钛矿和锐钛矿的形式存在．掺入适量的Sb后,由于Sb替代了TiO2的部分Ti形成Sb-O-Ti结构,改变了TiO2的晶格结构,改善了薄膜的结晶效率,使锐钛矿结构的TiO2:Sb含量明显提高．掺杂0．2％Sb时,薄膜的结晶效率最高．254 nm光源照射时,掺杂0．2％Sb的电极的阳极光电流密度可达42．49μA／cm2,是用同种方法制备的纯TiO2薄膜电极的近11倍;对亚甲基蓝具有最高分解性能,其一级反应速率常数为0．171 h／cm2,是未掺杂的纯TiO2薄膜的近2倍．     

双金属/TiO2纳米管复合结构中增强的光电流

将传统半导体材料与金属微纳结构相结合,利用其表面等离激元共振效应,可有效地增强复合结构的光电转换效率,使其广泛地被用于光电化学和光电探测等领域.本文以氧化铝纳米管为模板,采用原子层沉积技术制备出高有序的TiO2纳米管,并通过电子束热蒸发技术在大孔径的纳米管薄膜中分别负载金、铝和双金属金/铝纳米颗粒,形成金属纳米颗粒/TiO2纳米管复合结构.研究结果表明,相对于纯TiO2纳米管,Au/TiO2复合纳米管在568 nm的可见光照射下,其光电流密度约有400%的提高;在365 nm紫外光照射下,Al/TiO2复合纳米管的光电流提高约50%;同时负载双金属Au和Al纳米颗粒的TiO2纳米管在整个紫外-可见光区域光电流均显著增强.     

Hydrophilicity of amorphous TiO2 ultra-thin films

The UV-light-induced hydrophilicity of amorphous titanium dioxide thin films obtained by radio frequency magnetron sputtering deposition was studied in relation with film thickness. The effect of UV light irradiation on the film hydrophilicity was fast, strong and did not depend on substrate or thickness for films thicker than a threshold value of about 12 nm, while for thinner films it was weak and dependent on substrate or thickness. The weak effect of UV light irradiation observed for the ultra-thin films (with thickness less than 12 nm) is explained based on results of measurements of surface topography, UV-light absorption and photocurrent decay in vacuum. Comparing to thicker films, the ultra-thin films have a smoother surface, which diminish their real surface area and density of defects, absorb partially the incident UV light radiation, and exhibit a longer decay time of the photocurrent in vacuum, which proves a spatial charge separation. All these effects may contribute to a low UV light irradiation effect on the ultra-thin film hydrophilicity.     

基于金属掺杂ITO透明导电层的紫外LED制备

为降低ITO薄膜对紫外波段的光吸收，制备低电压高功率的紫外LED，研究了一种基于金属掺杂ITO透明导电层的365 nm紫外LED的制备工艺。利用1 cm厚的石英片生长了不同厚度ITO薄膜以及在ITO上掺杂不同金属的新型薄膜，并研究了在不同的退火条件下这种薄膜的电阻和透过率，分析了掺杂金属ITO薄膜的带隙变化。将这种掺杂的ITO薄膜生长在365 nm外延片上并完成电极生长，制备成14 mil×28 mil的正装LED芯片。利用电致发光（EL）设备对LED光电性能进行测试并对比。实验结果表明:掺Al金属的ITO薄膜能够相对ITO薄膜的带隙提高0.15 eV。在600℃退火后，方块电阻降低6.2 Ω/□，透过率在356 nm处达到90.8%。在120 mA注入电流下，365 nm LED的电压降低0.3 V，功率提高14.7%。ITO薄膜掺金属能够影响薄膜带隙，改变紫光LED光电性能。     

不同氧气流量对直流磁控溅射TiO2薄膜的影响

采用直流反应磁控溅射法,以高纯Ti为靶材,高纯O2为反应气体,制备了TiO2薄膜.研究了氧气流量对薄膜结晶取向、表面形貌和光学性能的影响.研究发现,TiO2薄膜主要呈锐钛矿TiO2(101)择优取向,当氧气流量较小时,薄膜中还含有金属Ti(100),氧气流量较大时,薄膜含TiO2(101)和TiO2(004),成多晶态;薄膜的粗糙度和颗粒大小都随氧气流量的增大而增大;薄膜在400～1 100nm可见-近红外波段有较高的透射率并且其吸收峰随着氧气流量的增大而红移,当氧气流量为5sccm时,平均透射率最高.     

Deposition of graded TiO2 films featured both hydrophobic and photo-induced hydrophilic properties

Graded TiO₂ films were deposited on unheated glass substrates by using a twin dc magnetron sputtering system. The graded TiO₂ films showed a highly polycrystalline structure of anatase with a little rutile phases revealed by X-ray diffraction spectra. The surface energy of the fresh and UV irradiated films were evaluated by water contact angle measurement. The results indicated that the water contact angle of the fresh graded TiO₂ films was found within 100-112°. The films then became a highly hydrophilic surface with the water contact angle of almost zero under 60 min UV irradiation. The XPS spectrum of Ti 2p revealed that the graded TiO₂ films became a stoichiometric titanium oxide layer near the surface, proving that titanium was fully oxidized. It was found that the surface OH group density depended on the substrates employed for given sputtering conditions. In addition, AFM images revealed a considerably rough surface of the graded films with RMS roughness of 12.6-14.5 nm. One can conclude that the unique properties of highly hydrophobicity and photo-induced hydrophilicity can be attributed to fully oxidized chemical composition and higher roughness on the film surface.     

制备温度对TiO2基膜表面非晶态ZnO薄膜发光特性影响的研究

利用电子束热蒸发镀膜的方式，以高纯度的ZnO和TiO₂颗粒为原料，以Si为基底在有氧的气氛中制备ZnO/TiO₂复合薄膜。研究制备温度对ZnO/TiO₂薄膜的结构以及发光性能的影响。通过拉曼(Raman)谱和X射线衍射(XRD)谱分析了ZnO/TiO₂薄膜的结构，表明所制备的ZnO薄膜为非晶态。用光致发光 (PL) 谱表征了它的发光特性，数据表明在250℃时制备的非晶态ZnO薄膜在波长389nm处具有极强的紫外光发射，在波长431nm处发出很强的紫光，在波长519nm处发出较强的黄绿光。     

钛酸锶钡薄膜的室温光学性能研究

采用溶胶-凝胶法制备了(Ba0.75Sr0.25)TiO3薄膜,研究了不同退火温度下样品的物相结构、薄膜的光致发光性能和光学透过率。结果表明:室温下非晶钛酸锶钡薄膜在蓝光激发下具有明显的发光现象,发光波长范围是500～650 nm,峰值在525 nm附近。延长非晶态薄膜的退火时间能够显著提高样品的发光强度,且发光强度随薄膜厚度增加而增大。晶态薄膜有微弱的发光现象。透射谱测试结果表明,钛酸锶钡薄膜在可见光范围内具有良好的光学透过率。     

Patterning of nanoparticulate transparent conductive ITO films using UV light irradiation and UV laser beam writing

Indium tin oxide (ITO) thin film is one of the most widely used as transparent conductive electrodes in all forms of flat panel display (FPD) and microelectronic devices. Suspension of already crystalline conductive ITO nanoparticles fully dispersed in alcohol was spun, after modifying with coupling agent, on glass substrates. The low cost, simple and versatile traditional photolithography process without complication of the photoresist layer was used for patterning ITO films. Using of UV light irradiation through mask and direct UV laser beam writing resulted in an accurate linear, sharp edge and very smooth patterns. Irradiated ITO film showed a high transparency (∼85%) in the visible region. The electrical sheet resistance decrease with increasing time of exposure to UV light and UV laser. Only 5 min UV light irradiation is enough to decrease the electrical sheet resistance down to 5 kΩ□.     

Photoinduced formation and aggregation of silver nanoparticles at the surface of carboxymethylcellulose films

Formation and aggregation of photolytic silver nanoparticles at the surface of silver salt of carboxymethylcellulose films (CMCAg films) have been investigated. Detailed X-ray photoelectron spectroscopy (XPS) study and field emission type scanning electron microscopy (FE-SEM) observation have been carried out to characterize silver nanoparticles at the film surface. When the CMCAg films were irradiated with UV light in wet air at room temperature for 30–60 min, silver nanoparticles of ca. 10 nm size were formed at the irradiated surface. According to the FE-SEM observation, the growth of the particle diameter and aggregation of nanoparticles took place after prolonged irradiation, and finally, the irradiated side of the film surface was densely covered with the silver nanoparticles of ca. 35 nm size. Chemical composition analysis by the XPS measurements has confirmed the increase in the atomic concentration of silver with irradiation time. It is suggested that silver atoms and clusters can move in the film and precipitate at the irradiated surface.     

共轭聚合物聚对苯撑乙烯膜的光稳定性研究

采用UV-Vis吸收光谱、荧光光谱对MDMO-PPV膜和MEH-PPV膜进行了光稳定性测试，最大吸收峰为500nm，最大荧光强度峰分别为580和589nm。在氧的存在和光的辐射下，均可降低它们的荧光强度。运用非均相光催化氧化技术，利用固态纳米TiO2-PVC复合膜，对提高PPV膜的光稳定性进行了初探。     

Effects of γ rays irradiation on structure and property of TiO2 thin films

TiO₂ thin films were deposited on a glass substrate by the radio frequency magnetron sputtering method, and annealed for 2 h at temperatures of 550°C. Then, ⁶⁰Co γ rays with different doses were used to irradiate the resulting TiO₂ thin films. The surface features of films before and after irradiation were observed by scanning electron microscope (SEM). Simultaneously, the crystal structure and optical properties of films before and after irradiation were studied by X-ray diffraction (XRD), UV–VIS transmission spectrum and Photoluminescence (PL) spectrum, respectively. The SEM analysis shows that the film is smooth with tiny particles on the film surface, and non-crystallization trend was clear after irradiated with γ rays. The XRD results indicated that the structure of the film at the room temperature mainly exists in the form of amorphous and mixed crystal at a sputtering power of 200 W, and non-crystallinity was more obvious after irradiation. Obvious difference can be found for the transmissibility of the irradiated and pre irradiation TiO₂ films by the UV-VIS spectra. The color becomes light yellow, and the new absorption edge also appeared at about 430 nm. PL spectra and photocatalysis experiments indicate that the photocatalysis degradation rate of the TiO₂ films on methylthionine chloride solution irradiated with the maximum dose can be increased to 90%.