退火对聚合物有机发光器件的影响

制作了结构为ITO／MEH—PPV／AI的单层聚合物有机发光器件(PLED),在镀铝电极前后分别对器件进行高于MEH—PPV玻璃化温度的退火处理。结果表明,镀铝电极后的退火处理可使器件的效率提高30％左右,器件的寿命增加40％左右;而镀铝电极前的退火处理对器件影响不大。     

基于叠层结构的本体异质结有机太阳电池

研究了叠层结构的本体异质结有机太阳电池,下层电池由共轭聚合物（MEH-PPV）作为光敏层,上层电池由共轭聚合物（1VIEDPPV）和ZnO纳米颗粒（50nm）组成光敏层。器件结构为ITO／PEDOT：PSS／MEHPPV／Ag／MEH-PPV：ZnO／Al。与单层有机太阳电池（ITO／PEDOT：PSS／MEH-PPV／Al）相比,叠层结构的开路电压Voc是单层电池的3．7倍,短路电流Jsc是单层电池的1．6倍。     

热交链NPD二聚体空穴注入层对PLED性能的改善

基于在PEDOT层上旋涂可热交链的NPD二聚体（VB-NPD）做空穴注入层实现高效率的聚合物发光二极管（PLED）,采用的器件结构为ITO／PEDOT（40nm）／VB-NPD／PFBT5（40nm）／TPBI（20nm）／CsF（1nm）／Al（i00rim）。通过调节VB-NPD层的厚度发现,当VB-NPD层的厚为...     

有机无机复合膜发光器件的研究

针对聚合物电致发光（EL）材料缺乏可用的电子型聚合物半导体材料的现状，采用无机电子型半导体材料ZnO：Zn与空穴型聚合物材料poly（2，5bis（dodecyloxy）-phenylenevinylene）（PDDOPV）成功制备了结构为ITO／PDDOPV／ZnO：Zn／Al的有机／无机复合膜双层器件。复合膜器件的发光效率与亮度比单层器件提高了1个数量级以上，而复合膜的电流是单层器件的0．5倍。而且，聚合物／无机物复合膜器件的发光颜色随电压的增加而蓝移，其光致发光（PL）光谱也随激发波长的改变而改变，有可能形成了新的发光基团。     

有机／聚合物超晶格结构制备及其电致发光器件

报道了选用有机小分子材料８－羟基喹啉铝（Ａｌｑ３）和聚合物材料聚乙烯基卡唑（ＰＶＫ）分别作为阱层材料和垒层材料，利用多源型高真空有机分子沉积系统进行有机／聚合物超晶格结构材料和制备，在结构特性和光学特性分析基础上。制备了这种超晶格结构的电致发光器件。     

基于接触式极化法的M—Z型聚合物电光调制器

基于接触式电极化法对Mach-Zehnder(M-Z）型有机聚合物电光强度调制器进行了研制，所研制的器件，在1550nm光波波长下，半波电压约为45V，消光比大于20dB，器件可以在推挽方式下进行工作，测得器件结构引入的损耗小于0．5dB，电极化后所具有的聚合物电光系数为11．1pm/V .     

ZnS:TbOF薄膜结晶性及不同复合绝缘层绿色ACTFEL器件特性的研究

为了改善ACTFEL器件的性能，本文就射频磁控溅射ZnS∶TbOF薄膜结晶性随溅射淀积条件的变化进行了研究，得出最佳选择：射频功率密度1．54W／cm2，衬底温度175℃，压强0．67Pa，溅射气体为纯Ar。同时，制备了几种不同复合绝缘层结构的绿色ACTFEL器件并就其性能作了比较。得出最佳结构：ITO／SiO_2／Ta_2O_5／ZnS：TbOF／SiO_2／Ta_2O5／Al。这说明了高电阻率介质用作与发光层相邻的第二绝缘层可以改善器件发光特性。     

GaAlAs／GaAs多量子阶增益耦合型DFB激光器／电吸收型调制器单片光子集成器件

我们在国际上率先提出将增益耦合型分布反馈式（ＧＣ－ＤＦＢ）半导体激光器作为激光器／调制器单片集成器件的光源．为了简化制作工艺，进一步提出激光器的有源层与调制器波导共用同一组分和同一结构．本文从理论上分析了该新型器件的可行性，优化设计了器件结构．在此基础上，采用金属有机化合物化学汽相外延技术（ＭＯＣＶＤ）在国际上首次研制成功了该种增益耦合型ＤＦＢ激光器／电吸收型调制器单片光子集成器件．器件阈值电流为３５ｍＡ，在—５Ｖ调制电压下消光比达５ｄＢ．静态调制过程中，激射波长与阈值没有变化．     

低功耗有机/无机混合结构热光开关的研制

利用聚合物材料SU-8作为芯层、聚合物材料PMMA作为上包层和无机材料SiO2作为下包层,设计并研制了一种有机/无机混合结构的Mach-Zehnder干涉(MZI)热光(TO)开关。为了保证波导中的单模传输、减小模式辐射损耗和衬底泄露损耗、缩短响应时间并降低器件功耗,对其结构参数做了优化。利用化学气相沉积(CVD)、涂膜和湿法刻蚀等工艺制备了器件样品。在1 550nm工作波长下,器件的开和关状态的驱动功率分别为0和13mW(开关功率为13mW),开和关状态间的消光比为18.3dB。在方波驱动电压信号作用下,测得器件的上升和下降时间分别为126和134μs。与无机材料Si/SiO2和全聚合物材料研制的TO开关相比,本文研制的混合结构器件综合利用了芯层聚合物材料热光系数大、上/下缓冲层厚度均较小以及Si/SiO2导热系数大的优点,因此同时具备了较低的功耗和较快的响应时间,在光通信系统中具有较好的应用前景。     

柔性衬底黄光有机小分子电致发光器件

彩溅射技术在透明的塑性材料聚对苯二甲酸乙二酯（ＰＥＴ）薄膜之上形成一层ＩＴＯ导电膜,并对此替代常用的玻璃衬底制备了黄光柔性衬底有机小分子电致发光器件的结构为ＰＥＴ／ＩＴＯ／Ａ１ｑ３：Ｒｕｂ／Ａ１ｑ３／Ａ１。器件在１４Ｖ时亮度为１２０ｃｄ／ｍ＾２,并且器件在弯曲较大角度时仍然能正常使用,达到了使用柔性衬底的目的。     

Controlling optical properties of electrodes with stacked metallic thin films for polymeric light-emitting diodes and displays

A semi-transparent metallic film and a high optical absorbing film were constructed with stacking metallic films. Both films were used as cathodes for polymeric light-emitting diodes (PLEDs). The semi-transparent film was made of gold/aluminum/gold thin multilayers with its optical transparency of the device reaches as high as /spl sim/70% in the visible region without capping layer, and the electrical sheet resistance reduces below 10 /spl Omega//square. During illumination of the PLED, there was approximately 47% of light emitting from the top of the cathode surface, and 53% of light from the ITO side. The high optical absorbing film, also refer to as the black cathode, was constructed with four alternating layers of aluminum-silver, each aluminum or silver layer is 4 nm thick. The PLED with this black cathode demonstrated 126% enhancement of contrast under 1000 lx ambient illumination. The physical properties of these two cathodes were characterized by current-voltage measurement and atomic force microscopy. Ultraviolet-visible transmission spectroscopy and X-ray photoemission spectroscopy were also used to characterize the semi-transparent cathode and the black cathode respectively. For polymer light-emitting device, it is believed that morphology modification at each interface of the cathode plays a crucial role in determining the optical properties and conductivity of the over cathode.     

透明导电ITO欧姆接触的AlGaInP薄膜发光二极管

提出了一种透明导电氧化铟锡(ITO)欧姆接触的AlGaInP薄膜发光二极管(LED)的结构和制作工艺.在这个结构里,ITO还作为窗口层材料,增强电流扩展,并应用了高反射率的金属作为反光镜.用Au-Sn合金(Au∶Sn＝8∶2,重量比)作为焊料,把带有金属反光镜的AlGaInP LED(RS-LED)外延片倒装键合到GaAs基板上,并去掉外延GaAs衬底,把被GaAs衬底吸收的光反射出去.与常规AlGaInP吸收衬底LEDs(AS-LED)和带有分布布拉格反光镜(DBR)的AlGaInP吸收衬底LEDs(DBR-AS-LED)电、光特性的比较,用透明导电ITO做欧姆接触的AlGaInP薄膜RS-LED结构能极大提高光输出功率和发光强度.正向电流20 mA时,RS-LED的光输出功率分别是AS-LED和DBR-AS-LED的2.4倍和1.7倍;RS-LED 20 mA下峰值波长624 nm的轴向光强达到了179.6 mcd,分别是AS-LED 20 mA下峰值波长627 nm和DBR-AS-LED 20 mA下峰值波长623 nm轴向光强的2.2倍和1.3倍.     

Improved performance of lateral GaN-based light emitting diodes with novel buried CBL structure in ITO film and reflective electrodes

In this letter, lateral GaN-based Light Emitting Diodes (LEDs) with a SiO₂ current blocking layer (CBL) buried in the indium tin oxide (ITO) film and highly reflective metal materials have been proposed. Compared with the conventional CBL structure which was inserted between ITO film and p-type GaN, simulation results showed that LEDs with a buried CBL in the ITO film effectively facilitated current spreading under the CBL. We demonstrated that buried CBL was beneficial for suppressing current crowding (CC) effect around the edge of CBL and may facilitate higher LED efficiency. Furthermore, experimental results showed that LEDs with the buried structure we proposed showed lower working voltage and higher light output power (LOP) compared with those with conventional CBL structure. These results further confirmed that the buried CBL scheme was effective to reduce current crowding (CC) effect. In addition, highly reflective metal materials of Cr/Al/Pt/Au were employed to reduce light absorption and achieve high light extraction efficiency.     

多晶硅薄膜阳极微腔有机发光器件及其简化制备流程的研究

介绍了溶液法金属诱导晶化的p型掺杂多晶硅薄膜(p -poly-Si)的制备,并研究了它的电学特性和光学特性.由于p -MIC poly-Si薄膜具有比较好的电学特性,且在红光区域具有比较高的反射率与透射率和很小的吸收率,因此我们将它用作红光OLED的阳极.结果显示该器件的最大发光效率为5.88cd/A,比用ITO作阳极制备的OLED效率提高了57%.这是由于此薄膜对可见光比较高的反射率和阴极铝对可见光的很高反射性能,使之形成了一定Q值的微腔效应所至.这样,可以实现发光强度较高、单色饱和性较好的单色显示器件.本研究的意义还在于,由于此MOLED的p型掺杂MIC多晶硅阳极是与其共面型驱动TFT有源层、源/漏两极同层材料制备,即是TFT漏极的延伸;这样,不仅形成了高性能的AMOLED单色显示,而且也大大简化了AMOLED工艺流程,从而形成了简化流程的4-mask AMOLED基板制备工艺.     

Design of a MoOx/Au/MoOx transparent electrode for high-performance OLEDs

A MoO_x(top)/Au/MoO_x(bottom) multilayer was systematically designed for transparent electrodes in green OLEDs in terms of optical transmission and series resistance of the device. The enhancement in optical transmission of MoO_x/Au/MoO_x (MAM) structures is a result of a series of events, including the optical interference within the multilayers and the interaction of light with surface plasmon polaritons in the metal layer. For the maximum transmission, the optical interference occurring within the multilayers was simulated using a transfer matrix model to determine the optimum thickness of MoO_x layers, and then the thickness of the Au interlayer was experimentally optimized for extraordinary optical transmission. In addition, the series resistance added by the top MoO_x was characterized to confirm its negligible impact on the performance of the device. The optimum MoO_x (40 nm)/Au (10 nm)/MoO_x (40 nm) structure showed much higher transmission in the green-red region and lower sheet resistance than indium tin oxide (ITO). We have fabricated MAM-based OLEDs the driving voltage of which was significantly reduced to ∼5.5 V at a current density of 20 mA/cm², and the current efficiency (11.46 Cd/A) was higher than that (10.91 Cd/A) of ITO-based OLEDs, demonstrating that the MAM electrode is a potential replacement for ITO in optical devices.     

Simultaneous Improvement of Charge Generation and Extraction in Colloidal Quantum Dot Photovoltaics Through Optical Management

Inverted structure heterojunction colloidal quantum dot (CQD) photovoltaic devices with an improved performance are developed using single‐step coated CQD active layers with a thickness of ≈60 nm. This improved performance is achieved by managing the device architecture to simultaneously enhance charge generation and extraction by raising optical absorption within the depletion region. The devices are composed of an ITO/PEDOT:PSS/PbS‐CQD/ZnO/Al structure, in which the p–n heterojunction is placed at the rear (i.e., opposite to the side of illumination) of the devices (denoted as R‐Cell). Sufficient optical generation is achieved at very low CQD layer thicknesses of 45–60 nm because of the constructive interference caused by the insertion of ZnO between the CQD and the Al electrode. The power conversion efficiency (PCE) of R‐Cells containing a thin CQD layers (≈60 nm) is much higher (≈6%) than that of conventional devices containing CQD layers with a thickness of ≈300 nm (PCE ≈4.5%). This optical management strategy provides a general guide to obtain the optimal trade‐off between generation and extraction in planar p–n junction solar cells. In terms of device engineering, all the layers in our R‐Cells are fabricated using single coating, which can lead to compatibility with high‐throughput processes.     

制备工艺对聚合物电致发光器件稳定性的影响

探讨了发光层厚度以及复合阴极材料对聚合物电致发光器件稳定性的影响,并通过对同一器件在不同初始亮度下的寿命进行测试比较,得到了该器件寿命的加速老化因子.然后,通过计算得知,结构为ITO/PEDOT:PSS/MEH.PPV/Ba/Al的聚合物电致发光器件在初始亮度为100 cd/m2情况下的寿命高达10 124 h,基本上...     

Work‐Function Engineering of Graphene Anode by Bis(trifluoromethanesulfonyl)amide Doping for Efficient Polymer Light‐Emitting Diodes

Graphene has been considered to be a potential alternative transparent and flexible electrode for replacing commercially available indium tin oxide (ITO) anode. However, the relatively high sheet resistance and low work function of graphene compared with ITO limit the application of graphene as an anode for organic or polymer light‐emitting diodes (OLEDs or PLEDs). Here, flexible PLEDs made by using bis(trifluoromethanesulfonyl)amide (TFSA, [CF₃SO₂]₂NH) doped graphene anodes are demonstrated to have low sheet resistance and high work function. The graphene is easily doped with TFSA by means of a simple spin‐coating process. After TFSA doping, the sheet resistance of the TFSA‐doped five‐layer graphene, with optical transmittance of ≈88%, is as low as ≈90 Ω sq^?1. The maximum current efficiency and power efficiency of the PLED fabricated on the TFSA‐doped graphene anode are 9.6 cd A^?1 and 10.5 lm W^?1, respectively; these values are markedly higher than those of the PLED fabricated on pristine graphene anode and comparable to those of an ITO anode.     

二维亚波长结构对OLED光抽出特性的FDTD模拟研究

有机发光二极管(OLED)发光效率很大程度上受到器件中高折射率材料(ITO/有机物)对导波光能量的制约.通过使用时域有限差分(FDTD)方法,对在OLED中的氧化铟与氧化锡复合透明阳极ITO结构上覆盖二维正方以及三角排列SiNx圆柱光子晶体厚膜(PCS)的结构进行了数值模拟,并对这种全新结构对于提高束缚于高折射率材料中的光的抽取效率的效果进行了分析,并给出了最优化的几何参数.     

Plasmonic Nanocavity Organic Light‐Emitting Diode with Significantly Enhanced Light Extraction,Contrast, Viewing Angle,Brightness, and Low‐Glare

One central challenge in LEDs is to increase light extraction; but for display applications, other factors may have equal significance, such as ambient‐light absorption, contrast, viewing angle, image sharpness, brightness, and low‐glare. However, current LED structures enhance only some of the factors, while degrading the others. Here, a new organic LED (OLED) structure is proposed and demonstrated, with a novel plasmonic nanocavity, termed “plasmonic cavity with subwavelength hole‐array” (PlaCSH), and exhibits experimentally significant enhancements of all above factors with unprecedented performances. Compared to the conventional OLEDs (the same but without PlaCSH), PlaCSH‐OLEDs achieve experimentally: i) 1.57‐fold higher external‐quantum‐efficiency and light‐extraction‐efficiency (29%/32% without lens, 55%/60% with lens)—among the highest reported; ii) ambient‐light absorption not only 2.5‐fold higher but also broad‐band (400 nm) and nearly angle and polarization independent, leading to lower‐glare; iii) fivefold higher contrast (12 000 for 140 lux ambient‐light); iv) viewing angle tunable by the cavity length; v) 1.86‐fold higher normal‐view‐brightness; and vi) uniform color over all emission angles. The PlaCSH is an excellent optical antenna—excellent in both radiation and absorption of light. Furthermore, PlaCSH‐OLEDs, a simple structure to produce, are fabricated using nanoimprint over large‐area (≈1000 cm²), hence scalable to wallpaper size.