PTCBI作为阴极修饰层对Rubrene/C70器件性能的影响

制备了结构为ITO/MoO₃(6 nm)/Rubrene (30 nm)/C₇₀ (30 nm)/PTCBI(x nm)/Al (150 nm)器件, 研究了四羧基苝的衍生物PTCBI作为阴极修饰层对Rubrene/C₇₀有机太阳能电池的作用. 实验结果显示, 在C₇₀与Al电极之间插入PTCBI 后, 电池性能得到明显改善; 分析表明, 插入PTCBI后, 活性层与阴极形成了良好的欧姆接触, 提高了器件的内建电场, 同时PTCBI避免了激子与Al电极的接触, 减少了在制备过程中高动能Al对C₇₀的破坏. 进一步考察了PTCBI厚度对电池的性能的影响, 结果显示, 厚度为6 nm的PTCBI 层器件性能最佳, 其开路电压(V_OC)、填充因子(FF)、短路电流密度(J_SC)与功率转换效率(ηP)与未插入PTCBI修饰层的器件相比分别提高了70.4%, 55.5%, 125.1%, 292.2%. 当PTCBI的厚度大于6 nm时, 激子解离后产生的自由电子会在PTCBI与阴极界面积累, 导致器件J-V曲线出现S形.     

氧化锌电阻阀片中ZnO(002)/β-Bi_2O_3(210)界面结构的第一性原理研究

为了从物质微观结构上了解氧化锌避雷器阀片的性能,采用基于密度泛函理论的第一性原理方法对ZnO(002)/β-Bi_2O_3(210)界面结构进行弛豫和电子结构计算.结果表明弛豫后,原子间的键长发生改变.界面区域差分电荷密度图和原子布居分析可得ZnO层片中Zn原子电荷缺失,β-Bi_2O_3层片中O原子电荷富集,ZnO层片向β-Bi_2O_3层片转移电子电荷23.61e.晶界结构的内建电场由ZnO层片指向β-Bi_2O_3层片,内建电场是ZnO电阻阀片具有非线性伏安特性的重要原因.界面附近态密度表明界面的结合主要依靠ZnO层片中Zn原子与β-Bi_2O_3层片中O原子相互作用.计算显示ZnO(002)/β-Bi_2O_3(210)界面结合较强,界面能约为-4.203 J/m~2.本文研究结果对于研制高性能非线性伏安特性氧化锌电阻片提供了机理解释和理论支持.     

倒置异质结有机太阳能电池的电子传输层

制备了结构为ITO/BCP或Alq3(x=0,2,6,10,20,40 nm)/C60(50 nm)/Rubrene(50 nm)/MoO3(5nm)/Al(130 nm)的倒置异质结有机太阳能电池,其中BCP或Alq3作电子传输层。实验结果表明:当BCP或Alq3≤6 nm时,器件性能随电子传输层厚度的变化不大;当BCP或Alq3≥10 nm时,随电子传输层厚度的增加,含Alq3器件的性能衰减很快,含BCP器件的性能衰减相对较慢,且其开路电压保持不变。分析表明:当电子传输层较薄时,粗糙的ITO使电子较容易从C60注入到ITO;当电子传输层较厚时,BCP/C60之间的能带弯曲使二者之间几乎不存在势垒,含BCP器件性能较差主要源于BCP较差的电子迁移率,而含Alq3器件性能较差主要源于Alq3/C60之间的势垒。     

间隔层对红绿磷光有机电致发光器件发光性能的影响

制备了结构为ITO/MoO₃(40 nm)/NPB(40 nm)/TCTA(10 nm)/CBP∶GIr1(14%)∶R-4B(2%)(20 nm) /间隔层(3 nm)/ CBP∶GIr1(14%)∶R-4B(2%)(10 nm)/BCP(10 nm)/Alq₃(40 nm)/LiF(1 nm)/Al(100 nm) 的有机电致发光器件,间隔层分别为CBP,TCTA,TPBI和BCP,GIr1和R-4B分别为绿红磷光材料。通过加入不同间隔层来调控载流子和激子在发光层内的分布并研究了其对器件发光性能的影响。研究表明TCTA,TPBI和BCP分别作为间隔层的器件较CBP为间隔层的参考器件,电压为6 V时,电流效率分别高出59%,79%和93%,以BCP为间隔层的器件效率最高达到22.58 cd·A-1;TPBI和BCP为间隔层相对于以TCTA为间隔层的器件,在较高的电流密度下,效率滚降更小。分析原因TCTA间隔层较高的LUMO能级和三线态能量将电子和激子限制在较窄的复合区域,提高了载流子相遇形成激子的概率,在较高电流密度下猝灭也更严重;TPBI和BCP由于具有较高的HOMO能级和电子传输能力,拓宽了激子的复合区域。间隔层引起电子或空穴的累积,形成较高的空间电场,有利于发光层相应载流子的注入与传输。由于发光层掺杂方式为红绿共掺,器件均获得了较好的色坐标稳定性。     

电荷转移金属[60]富勒烯盐的光电性质

用物理喷束淀积技术制备了过渡金属[60]富勒烯盐C60Ni薄膜，研究了Al/C60Ni/ITO光电池的光伏效应和正反向电学特性并与Al/C60/ITO膜进行了比较。用界面偶极电场解释了Al/C60Ni界面光伏效应和整流应的增强，表明在该样品中发生的从Ni原子到C60的电子转移使Al/C60Ni界面偶极电场增强。     

原子层沉积Al2O3/n-GaN MOS结构的电容特性

利用原子层沉积技术制备了具有圆形透明电 极的Ni/Au/Al₂O₃/n-GaN金属-氧化物-半导体结构, 研究了紫外光照对样品电容特性及深能级界面态的影响, 分析了非理想样品积累区电容随偏压增加而下降的物理起源. 在无光照情形下, 由于极长的电子发射时间与极慢的少数载流子热产生速率, 样品的室温电容-电压扫描曲线表现出典型的深耗尽行为, 且准费米能级之上占据深能级界面态的电子状态保持不变. 当器件受紫外光照射时, 半导体耗尽层内的光生空穴将复合准费米能级之上的深能级界面态电子, 同时还将与氧化层内部的深能级施主态反应. 非理想样品积累区电容的下降可归因于绝缘层漏电导的急剧增大, 其诱发机理可能是与氧化层内的缺陷态及界面质量有关的“charge-to-breakdown”过程. 关键词： 原子层沉积 2O₃/n-GaN')" href="#">Al₂O₃/n-GaN 金属-氧化物-半导体结构 电容特性     

基于有机异质结C60/ZnPc的绿色磷光TOLED

以有机异质结C_(60)/ZnPc作为电荷产生层,制备结构为ITO/TPBi(40nm)/C_(60)(xnm)/ZnPc(x nm)/NPB(40nm)/Al(120nm)和ITO/TPBi(40nm)/LiF(ynm)/Al(2nm)/C_(60)(5nm)/ZnPc(5nm)/MoO_3(3nm)/NPB(40nm)/Al(120nm)的非发光倒置器件,其中x的值为0、5、10和15,y的值为0、0.5、1.0和1.5.实验证明,有机异质结C_(60)/ZnPc可在外电场下实现电荷分离,加入LiF/Al和MoO_3可更有效地提高电荷产生层的电荷分离和注入能力.基于LiF/Al/C_(60)/ZnPc/MoO_3结构,制备绿色磷光叠层有机发光二极管,进一步研究该电荷产生层对叠层器件的光电性能影响.结果表明,电荷产生层的电荷分离和注入可影响叠层器件内部的电荷注入平衡,进而对器件性能产生影响.当LiF、Al、C_(60)、ZnPc和MoO_3结构厚度分别为0.5nm、1nm、5nm、5nm和3nm时,电荷产生层产生的电荷与两侧电极注入的电荷达到匹配,使叠层器件具有最佳光电性能,获得了高效绿色磷光叠层器件,其驱动电压明显低于单层器件2倍,最大亮度、电流效率和功率效率分别达84 660cd·m~(-2)、94.7cd·A~(-1)和43lm·W~(-1).     

Al_2O_3薄层修饰SiN_x绝缘层的IGZO-TFTs器件的性能研究

采用原子层沉积工艺(ALD)生长均匀致密的三氧化二铝(Al2O3)薄层对氮化硅(Si Nx)绝缘层进行修饰,研究了铟镓锌氧薄膜晶体管(IGZO-TFTs)器件的性能。当Al2O3修饰层厚度为4 nm时,绝缘层-有源层界面的最大缺陷态密度相比于未修饰器件降低了17.2%,器件性能得到显著改善。场效应迁移率由1.19 cm2/(V·s)提高到7.11 cm2/(V·s),阈值电压由39.70 V降低到25.37 V,1 h正向偏压应力下的阈值电压漂移量由2.19 V减小到1.41 V。     

电致发光加速层二氧化硅的电子高场迁移率

根据非晶态半导体的能带理论，讨论了分层优化薄膜电致发光方案中非晶二氧化硅加速层中的电子在高电场中的输运行为.研究结果表明：在高电场下，由于电场的存在降低了陷阱之间的平均势垒高度.在费密能级附近处的杂质及缺陷定域态和导带尾定域态中，电子的输运主要表现为电场增强的热辅助式跳跃传导；而在导带扩展态中，电子的输运仍像晶态半导体那样表现为共有化运动.此外，以实验数据为基础，计算出了非晶二氧化硅中电子的迁移率、最小金属电导率、导带迁移率边界状态密度及费密能级处的状态密度. 关键词：     

以表面修饰铯掺杂ZnO纳米柱阵列为电子传输层的太阳能电池

通过化学水浴法生长了铯掺杂ZnO纳米柱阵列(CZO-NRA),将其作为电子传输层(ETL),利用乙醇胺与二甲氧基乙醇共混溶液对CZO-NRA进行表面修饰,制备了倒置聚合物太阳能电池。研究结果表明,适量的铯掺杂提高了纳米柱的c轴择优取向结晶度,减少了ETL中由氧空位和锌填隙原子引起的深能级缺陷,减小了器件的串联电阻,增大了器件的短路电流与填充因子。表面修饰减少了CZO-NRA的表面缺陷,减小了ETL与有源层的接触电阻,抑制了界面载流子复合。与未掺杂的器件相比,表面修饰CZO-NRA器件的能量转换效率由1.27%提高至2.89%。     

High-efficiency Simple Structure White Organic Light-emitting Devices Based on Rubrene Ultrathin Layer

White organic light-emitting devices (WOLEDs) were fabricated with an ultrathin layer of rubrene inserted between NPB and TPBI. With a simple three-layer structure of ITO/NPB(50 nm)/rubrene(0.1 nm)/TPBI(50 nm)/LiF/Al, a white light with CIE coordinates of (0.31, 0.30) were generated. The device gave a maximum luminance efficiency of 2.04 lm/W at 5 V. Furthermore, with a multilayer structure of ITO/m-MTDATA(30 nm)/NPB(20 nm)/rubrene(0.1 nm)/TPBI(40 nm)/Alq₃(10 nm)/LiF/Al, the device reached a maximum luminance efficiency of 4.29 lm/W at 4 V and the luminance could exceed 10 000 cd/m² at 10 V.     

New double graded structure for enhanced performance in white organic light emitting diode

This study presents a new design that uses a combination of a graded hole transport layer (GH) structure and a gradually doped emissive layer (GE) structure as a double graded (DG) structure to improve the electrical and optical performance of white organic light-emitting diodes (WOLEDs). The proposed structure is ITO/m-MTDATA (15 nm)/NPB (15 nm)/NPB: 25% BAlq (15 nm)/NPB: 50% BAlq (15 nm)/BAlq: 0.5% Rubrene (10 nm)/BAlq: 1% Rubrene (10 nm)/BAlq: 1.5% Rubrene (10 nm)/Alq₃ (20 nm)/LiF (0.5 nm)/Al (200 nm). (m-MTDATA: 4,4′,4″ -tris(3-methylphenylphenylamino)triphenylamine; NPB: N,N′-diphenyl-N,N′-bis(1-naphthyl-phenyl)-(1,1′-biphenyl)-4,4′-diamine; BAlq: aluminum (III) bis(2-methyl-8-quinolinato) 4-phenylphenolate; Rubrene: 5,6,11,12-tetraphenylnaphthacene; Alq₃: tris-(8-hydroxyquinoline) aluminum). By using this structure, the best performance of the WOLED is obtained at a luminous efficiency at 11.8 cd/A and the turn-on voltage of 100 cd/m² at 4.6 V. The DG structure can eliminate the discrete interface, and degrade surplus holes, the electron-hole pairs are efficiently injected and balanced recombination in the emissive layer, thus the spectra are unchanged under various drive currents and quenching effects can be significantly suppressed. Those advantages can enhance efficiency and are immune to drive current density variations.     

非掺杂型高效绿色磷光有机电致发光器件

在空穴传输层TCTA与电子传输层TPBi之间引入磷光染料Ir(ppy)3超薄发光层,制备了结构为ITO/MoO_3(2 nm)/NPB(40 nm)/TCTA(10 nm)/Ir(ppy)3(xnm)/TPBi(40 nm)/LiF(1 nm)/Al(80 nm)的非掺杂磷光有机电致发光器件。通过调控非掺杂发光层的厚度,详细研究了Ir(ppy)3层厚度对器件性能的影响。实验结果表明,当非掺杂发光层厚度为0.2 nm时,器件的性能最好,器件的亮度、效率和外量子效率分别达到26 350 cd·m~(-2)、42.9 cd·A~(-1)和12.9%。研究结果表明,采用超薄的非掺杂发光层可以简化器件结构和制备工艺,获得高效率的OLED器件。     

Efficient and stable single-dopant white OLEDs based on 9,10-bis (2-naphthyl) anthracene

Efficient white organic light-emitting diodes (WOLEDs) are fabricated with a thin layer of 9,10-bis (2-naphthyl) anthracene (ADN) doped with Rubrene as the source of white emission. A device with the structure of ITO/NPB (70 nm)/ADN: 0.5% Rubrene (30 nm)/Alq₃ (50 nm)/MgAg shows a maximum current efficiency of 3.7 cd/A, with the CIE coordinates of x=0.33, y=0.43. The EL spectrum of the devices and the CIE coordinates remains almost the same when the voltage is increased from 10 to 15 V and the current efficiency remains quite stable with the current density increased from 20 to 250 mA/cm².     

Analysis of hybrid donor layer in organic solar cells based on SubPc and rubrene

In this paper, photovoltaic characteristics of ITO/PEDOT:PSS/SubPc:Rubrene (mixed ratio R by weight)/C₆₀/Bphen/Ag organic solar cells (OSCs) are analyzed in detail. The intrinsic properties of a SubPc:rubrene doped layer on device performance were discussed based on theoretical analysis of the experimental OSCs. The ratio R was 0, 0.25, 0.5, and 0.75,1, respectively. The results showed that when R was 0.75 performing the best, which owned the highest short circuit current (J _sc ) 6.61 mA/cm² and highest power conversion efficiency (PCE) 2.44%, the FF was 41% and the open circuit current (V _oc ) was 0.905 V. The suitable HOMO level, absorption capacity, carrier transport ability and exciton diffusion length (L _D ) of organic material are very important for the performance of the device.     

发光层和空穴传输层对白色电致发光器件性能的影响

利用电子传输性能良好的苯并噻唑螯合锌(Zn(BTZ)₂)作为蓝光层，通过设计不同类型的空穴传输层并试验不同厚度的发光层后，制作了一种最佳厚度的双发光层白色电致发光器件：氧化铟锡(ITO)/N-N′-双(3-甲基苯基)-N-N′-二苯基-1-1′-二苯基-4-4′-二胺(TPD)∶N,N′-二(1-萘基)-N,N′-二苯基-1,1′-联苯-4-4′-二胺(NPB)(1∶0.0 关键词： 厚度 空穴传输层 白光 载流子     

Efficient bright white organic light-emitting diode based on non-doped ultrathin 5,6,11,12-tetraphenylnaphthacene layer

High-performance undoped white organic light-emitting diode (OLED) has been fabricated using an ultrathin yellow-emitting layer of 5,6,11,12-tetraphenylnaphthacene (rubrene) inserted at two sides of interface between two N,N′-bis-(1-naphthyl)-N,N′- biphenyl-1,1′-biphenyl-4,4′- diamine (NPB) layers as a hole transporting and blue emissive layer, respectively. The results showed that a maximum luminance of the device reached to as high as 21,500 cd/m² at 15 V. The power efficiencies of 2.5 and 1.6 lm/W at a luminance of 1000 and 10000 cd/m², respectively, were obtained. The peaks of electroluminescent (EL) spectra locate at 429 and 560 nm corresponding to the Commissions Internationale De L’Eclairage (CIE) coordinates of (0.32, 0.33), which is independent of bias voltage. The performance enhancement of the device may result from direct charge carrier trapping in rubrene. Energy transfer mechanism was also found in the EL process.     

荧光染料掺杂的高效率、高亮度白色有机电致发光器件

制备了结构为 ITO/NPB（30 nm）/Rubrene（0.2 nm）/CBP：Bczvbi（8 nm,x%）/Bphen（30 nm）/Cs₂CO₃：Ag₂O（2 nm,20%）/Al（100 nm）的器件。研究了Bczvbi掺杂浓度（x=5,10,15）对白光器件性能的影响。综合利用发光层中主客体之间的能量转移和空穴阻挡层的空穴阻挡特性,得到了高效率、高亮度的白色有机电致发光器件。当Bczvbi的掺杂质量分数为10%时,器件的效率和亮度都为最大。驱动电压为7 V时,最大电流效率为4.61 cd/A;驱动电压为9 V时,最大亮度为21 240 cd/m²。当驱动电压从4 V增加到9 V时,色坐标从（0.36,0.38）变化为（0.27,0.29）,均处于白光区域。