有机电致发光(OLED)材料的研究进展

有机电致发光器件(OLED)具有效率高、亮度高、驱动电压低、响应速度快以及能实现大面积光电显示等优点,在平板显示和高效照明领域具有极大的应用前景而引起广泛关注。详细介绍了有机电致发光材料的种类、组成、特点和研究近况,并对其用途和前景做了一定的介绍。     

Reactive DC Magnetron Sputtering Deposition of Copper Nitride Thin Film

Copper nitride thin film was deposited on glass substrates by reactive DC （direct current） magnetron sputtering at a 0.5 Pa N2 partial pressure and different substrate temperatures. The as-prepared film, characterized with X-Ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy measurements, showed a composed structure of Cu3N crystallites with anti-ReO3 structure and a slight oxidation of the resulted film.The crystal structure and growth rate of Cu3N films were affected strongly by substrate temperature. The preferred crystalline orientation of Cu3N films were （111） and （200） at RT, 100℃. These peaks decayed at 200℃ and 300℃ only Cu （111） peak was noticed. Growth of Cu3N films at 100℃ is the optimum substrate temperature for producing high-quality （111） Cu3N films. The deposition rate of Cu3N films estimated to be in range of 18-30 nm/min increased while the resistivity and the microhardness of Cu3N films decreased when the temperature of glass substrate increased.     

Fabrication and Properties of DC Magnetron Sputtered Indium Tin Oxide on Flexible Plastic Substrate

Indium tin oxide (ITO) thin films deposited on flexible polyethylene terephthalate (PET) substrates at low temperature by DC magnetron sputtering from an In-Sn (90-10 wt pct) alloy target were studied. The correla-tion between deposition conditions and ITO property was systematically investigated and characterized. These as-deposited ITO films were used as the anode contact for flexible organic light-emitting diodes (FOLEDs). The fabricated FOLEDs with a structure of PET/ITO/NPB (50 nm)/Alq (20 nm)/Mg:Ag (100 nm) showed a maximum luminance of 2125 cd/m2 at 13 V.     

磁控溅射低温沉积ITO薄膜及其光电特性研究

采用直流反应磁控溅射法低温沉积ITO薄膜,用XRD、SEM和UV—Vis分别表征ITO薄膜的晶体结构、表面形貌及其紫外-可见光吸收谱,研究了氧分压、溅射功率及薄膜厚度等工艺参数对薄膜光电性能的影响,结果表明,氧分压过大时,ITO薄膜中有大量的位错和缺陷,使薄膜的电阻率变大,导电性变差;氧分压过小时,薄膜中将有大量氧空位产生,导致晶格变形,使电阻率增加。随着溅射功率增大,在相同时间内薄膜厚度增加,方块电阻减小,薄膜电阻率降低。随着薄膜厚度增加,制备的薄膜晶体结构相对完整,载流子浓度和迁移率逐渐增大,薄膜电阻率变小,进而对样品的光电性能产生明显影响。     

温度对直流反应磁控溅射制备TiO2薄膜光学性质的影响

应用DC(直流)反应磁控溅射设备在硅基底上制备TiO2薄膜,在固定的电源功率下,氩气流量为42.6sccm,氧流量为15sccm,溅射时间为30分钟的条件下,通过控制温度改变TiO2薄膜的光学性质.应用n&k Analyzer 1200测量,当温度增加时薄膜的平均反射率降低同时反射低谷向长波方向移动;温度对消光系数k影响不大;当温度低于180℃薄膜的折射率变化不大,当温度达到240℃左右时薄膜的折射率明显降低.通过XRD和SEM表征发现,随着温度的增加TiO2的晶体结构由混晶变为单一的锐钛矿相,薄膜表面的颗粒由多变少,表面形貌由粗糙多孔变得细腻平滑.     

离子束增强反应磁控溅射低温快速沉积AlN膜

本文采用氮离子束增强反应磁控溅射,在低温下沉积了 AlN 薄膜.用 X 射线衍射和 X 射线光电子谱对薄膜的晶体结构和电子结构进行了分析,结果表明,随着离子源中氮离子束流的增加,薄膜组成由面心立方的 Al 转变为密排立方的 AlN.氮离子在薄膜制备中的引入,有效地降低了沉积温度,提高沉积速率,并实现了薄膜 N/Al 化学计量比的控制.对 AlN 薄膜的紫外-可见光透射谱和红外吸收谱也进行了测定.     

非织造布表面反应溅射沉积ZnO薄膜及其结构与性能分析

实验采用低温直流磁控溅射技术，经O2和Zn在真空腔内反应、在涤纶纺粘非织造布表面沉积ZnO功能性纳米薄膜。运用能量散射X射线能谱仪（EDX）分析样品镀层前后元素组成的变化及其含量，并利用原子力显微镜（AFM）分析纳米结构表面镀层的形貌及其与直流溅射工艺参数的关系。分析表明：ZnO颗粒尺寸在一定范围内随氧氩比的增大而增大，氧氩比为20sccm：20sccm时较合适；溅射功率和镀膜厚度的增加均使ZnO颗粒尺寸增大，溅射功率过大会导致ZnO颗粒发生畸变；溅射压强增加颗粒直径则是先增大后减小，同时压强增大颗粒均匀性和取向性变差。利用织物感应式静电测试仪测试镀层前后织物的抗静电性能，发现经镀层后非织造布的抗静电性能得到了显著的改善，而且随着膜厚的增加抗静电性能提高也很明显。     

总气压对直流反应磁控溅射制备TiO2薄膜的光学性质的影响

用DC(直流)反应磁控溅射设备在硅基底上制备TiO2薄膜，在固定电源功率、氩气流量42．6sccm、氧流量15sccm、溅射时间30min的条件下，通过控制总气压改变TiO22薄膜的光学性质。应用n＆k Analyzer 1200测量，当总气压增加时薄膜的平均反射率降低，同时反射低谷向短波方向移动，总气压对消光系数k影响不大；随着总气压的增加薄膜的折射率出现了下降的趋势，但当总气压达到一定量值时折射率的变化趋于稳定。通过XRD和SEM表征发现，随着总气压的增加TiO2的晶体结构由金红石相向锐钛矿相转变，薄膜表面的颗粒度大小由粗大变得微小细密。     

室温下制备非晶ZnO薄膜及其电阻开关特性研究

室温下采用紫外固化的方法取代溶胶-凝胶方法中的高温退火制备了氧化锌薄膜, XRD分析结果表明薄膜为非晶的, XPS分析结果表明薄膜的主要成分是ZnO。在深紫外固化后的薄膜表面溅射Al作为顶电极获得Al/a-ZnO/FTO结构的器件,研究深紫外照射时间对器件电阻转变性能的影响, 进一步解释了深紫外固化的机制。研究表明: 经过充足时间(12 h)照射的器件表现出双极性电阻开关特性,阈值电压分布集中(-3.7 V<V_set<-2.9 V, 3.4 V< V_reset<4.3 V)且符合低电压工作的要求, 至少在4000 s内器件的高低阻态都没有发生明显的退化, 表现出了良好的存储器特性。Al/a-ZnO/FTO器件的这种电阻转变特性可以用空间电荷限制电流传导机制解释。     

SiO_2/Si上直流磁控反应溅射制备AlN薄膜

利用正交设计分析了直流磁控溅射中溅射气压,衬底温度和N2浓度对SiO2/Si衬底上制备的AlN薄膜的(002)择优取向的影响水平。利用X-射线衍射(XRD)、场发射扫描电镜(FESEM)、原子力显微镜(AFM)对薄膜的晶向和表面形貌进行了分析,得到制备高度择优取向的AlN薄膜的最佳期望条件:衬底温度为250℃,溅射气压为2Pa,N2浓度为75%;并得出了氮气浓度对薄膜的(002)择优取向的影响较大。具有择优取向的AlN薄膜的折射率约为2.06。     

基底温度和氧分压对直流磁控溅射制备的ZnO∶Al薄膜性能的影响

利用直流磁控溅射法在玻璃衬底上制备了ZnO:A l(ZAO)透明导电薄膜。详细研究了沉积时的基片温度、氧分压强对膜的透光率和电阻率的影响。结果表明:ZAO薄膜具有六角纤锌矿结构且呈c轴择优取向,晶粒垂直于衬底方向柱状生长;衬底温度和氧分压对薄膜的电阻率有很大影响;基底温度对薄膜的可见光透过率影响不大,但随氧分压的增大而增大;在衬底温度为250℃、氧分压为1%时,薄膜有最优化的电阻率和平均透光率,分别达到8.35×10-4Ω.cm和85.2%。     

退火温度对TiO2薄膜结构和表面形貌的影响

研究了退火温度对中频交流反应磁控溅射技术制备的TiO2 薄膜结构和表面形貌的影响。利用X射线衍射仪和原子力显微镜 ,检测了TiO2 薄膜的晶体结构和表面形貌。实验结果显示 :沉积态TiO2 薄膜为非晶态 ;低温 (70 0℃以下 )退火后 ,TiO2 薄膜出现锐钛矿相 ,晶粒长大不明显 ;高温退火 (90 0℃以上 )后 ,薄膜转变为金红石相 ,晶粒由柱状转变为棱状 ,并迅速长大至微米量级     

Multiphotoluminescence from a Triphenylamine Derivative and Its Application in White Organic Light‐Emitting Diodes Based on a Single Emissive Layer

White organic light‐emitting diode (WOLED) technology has attracted considerable attention because of its potential use as a next‐generation solid‐state lighting source. However, most of the reported WOLEDs that employ the combination of multi‐emissive materials to generate white emission may suffer from color instability, high material cost, and a complex fabrication procedure which can be diminished by the single‐emitter‐based WOLED. Herein, a color‐tunable material, tris(4‐(phenylethynyl)phenyl)amine (TPEPA), is reported, whose photoluminescence (PL) spectrum is altered by adjusting the thermal annealing temperature nearly encompassing the entire visible spectra. Density functional theory calculations and transmission electron microscopy results offer mechanistic understanding of the PL redshift resulting from thermally activated rotation of benzene rings and rotation of 4‐(phenylethynyl) phenyl)amine connected to the central nitrogen atom that lead to formation of ordered molecular packing which improves the π–π stacking degree and increases electronic coupling. Further, by precisely controlling the annealing time and temperature, a white‐light OLED is fabricated with the maximum external quantum efficiency of 3.4% with TPEPA as the only emissive molecule. As far as it is known, thus far, this is the best performance achieved for single small organic molecule based WOLED devices.     

Diamond Film Synthesis with a DC Plasma Jet： Effect of the Contacting Interface between Substrate and Base on the Substrate Temperature

The contacting interface between the substrate and water-cooled base is vital to the substrate temperature during diamond films deposition by a DC （direct current） plasma jet. The effects of the solid contacting area,conductive materials and fixing between the substrate and the base were investigated without affecting the other parameters. Experimental results indicated that the preferable solid contacting area was more than 60% of total contacting areal; the particular Sn-Pb alloy was more suitable for conducting heat and the concentric fixing ring was a better setting for controlling the substrate temperature. The result was explained in terms of the variable thermal contact resistance at the interface between substrate and base. The diamond films were analyzed by scanning electron microscopy （SEM） for morphology, X-ray diffraction （XRD） for the intensity of characteristic spectroscopy and Raman spectroscopy for structure.     

退火温度和ZnO缓冲层对氨化Ga2O3/ZnO薄膜合成GaN纳米结构的影响

利用射频磁控溅射法在Si(111)衬底上先溅射ZnO缓冲层,再溅射Ga2O3薄膜,然后在开管炉中不同温度下通氨气进行氨化反应生长GaN薄膜.分析结果表明,利用该方法制备的GaN薄膜是六角纤锌矿多晶结构,并且随着氨化温度的升高,GaN薄膜向棒状和线状形态转变.同时分析了ZnO缓冲层对形成GaN纳米结构的影响.     

复合新型保鲜膜的制备及对低温草鱼质量的影响

目的 开发一种具有优良理化性能和保鲜效果的新型生物保鲜膜。方法 以普鲁兰多糖和魔芋胶为基材,通过添加不同浓度的鱼胶原蛋白制备新型复合生物保鲜膜,结合其水溶性、透光性和质构性等指标,研究鱼胶原蛋白对复合膜物理性能的影响,并以TVB-N值、pH值、细菌总数和丙二醛含量及汁液流失率为指标,探讨在低温下复合生物膜对草鱼的保鲜效果。结果 鱼胶原蛋白能改善多糖保鲜膜的理化性能,且在其质量分数为3%时的性能最佳;将经不同涂膜处理的草鱼置于4℃下储藏12 d,结果表明,采用质量分数为3%的鱼胶原蛋白涂膜处理可延缓鱼肉的腐败、肉制品中食源性病原菌的滋生及挥发性盐基氮的生成,有效延缓了脂质和蛋白质的氧化变质进程。结论 采用质量分数为3%的鱼胶原蛋白能改善多糖基生物保鲜膜的物理性能和生物性能,显著保持其质构性能,可将草鱼的货架期从4 d延长至9～10 d,该新型复合保鲜膜具有良好的应用价值和开发前景。