一种新型Ir(Ⅲ)配合物磷光材料的电致发光性能研究

合成了一种新的磷光Ir(Ⅲ)配合物Ir(NCPy)2acac,其中NCPy和acac分别代表9-(2-萘基)-3-吡啶-咔唑和乙酰丙酮。利用该配合物制备了掺杂的有机发光二极管(OLEDs)。其中掺杂器件在513nm处有较强的金属配合物三重态的绿色磷光发射,最大亮度为24340cd/m2,最大电流效率为16.45cd/A,色坐标为(0.26,0.62),是首次报道的新型Ir(Ⅲ)配合物绿色磷光材料。     

一种正丙基环己烷修饰红光铱(Ⅲ)配合物的合成与发光性能研究

为了提高铱配合物材料的溶解性,同时具有较高的热稳定性,将正丙基环己烷引入到配体中合成了一种新型结构的红色磷光铱(Ⅲ)配合物Ir(pcpiq)₂acac (pcpiq=1-[4-(4-丙基环己基)苯基]异喹啉,acac=乙酰丙酮负离子)。通过紫外-可见光吸收光谱、荧光发射光谱、循环伏安测试和差热扫描分析对其光学性能、电化学性能和热稳定性进行了研究。以其作为发光材料,按照4~12%的掺杂浓度,分别以真空蒸镀和溶液旋涂工艺制备了有机电致发光器件(OLED)。结果显示,以Alq3为主体的蒸镀工艺制备的器件,EL光谱发射峰位于639 nm,亮度达到5 987 cd/m²,10 V电压时电流效率和功率效率分别为6.11 cd/A和1.64 lm/W,器件发出了较纯正的红光,其色坐标位于(0.68,0.32)。     

一种基于液晶性质的Pt配合物磷光材料电致发光器件

采用聚合物掺杂的方式,利用旋涂工艺制备了ITO/PVK:TOPPt/BCP(20 nm)/Mg:Ag(200 nm)结构的有机电致发光器件(OLED)。对掺杂浓度为2%(器件A)和4%(器件B)的磷光聚合物掺杂体系的光致发光(PL)和电致发光(EL)性质进行了分析研究,并对主体材料PVK到磷光客体材料TOPPPt的能量传递机制进行了讨论。实验表明,器件的EL谱谱峰位于625 nm,器件A在25 V时最大亮度为3037 cd/m2,最大电流效率为3.15cd/A。器件的EL谱不会随着偏置电压和掺杂浓度而改变,器件具有较好的稳定性。     

新型宽谱带黄色磷光铱(Ⅲ)配合物的合成、光物理性质及其高效电致发光

发展新型高性能黄色磷光材料是实现高品质互补色白光有机发光器件(OLEDs)的关键.本工作中,使用氯原子功能化的2-苯基喹啉衍生物作为环金属配体,乙酰丙酮作为辅助配体,通过温和的合成方法制备了一种新型氯功能化的黄色磷光铱(Ⅲ)配合物(Ir1).通过核磁共振谱和单晶X-射线衍射确认了配合物的结构.该配合物在二氯甲烷中具有强...     

利用新型磷光材料Ru(dtb-bpy)3·2(PF6)提高白光LED的显色指数

为了提高白光发光二极管(LED)的显色指数,在传 统白光LED的YAG粉胶层之上分别滴加0.0、 1.0、3.0、4.0和5.5mgRu(dtb-bpy)3·2(PF6)的四氢呋喃溶液,制备了5种 白光LED样品,并对样品的发光特性进行了检测。结果表明,随着Ru(dtb-bpy)3∶2(PF6) 材 料含量的增加,样品的发光强度逐渐减弱,发光光谱出现红移现象;并且Ru(dtb-bpy)3· 2(PF6)有一最佳含量,即当滴加的Ru(dtb－bpy)3·2(PF6)溶液为4.0mg时,LED样 品的显色指数(CRI)有明显提高,达到最高值为84.5。     

新型稀土配合物红色有机电致发光器件

合成了一种新型的共掺杂稀土Eu-Gd配合物Gd0.5Eu0.5(TTA)3Dipy,将其作为红光发射材料制备了结构为ITO/PVK:Gd0.5Eu0.5(TTA)3Dipy/PBD/Al的有机电致发光薄膜器件,得到了单色性好的红色有机电致发光器件,器件的开启电压为9 V,在16 V时达到最大亮度109 nit.研究了Eu-Gd配合物与PVK共掺杂体系的激发光谱和光致发光谱,结果发现两者间存在着能量转移,表明Gd3 的存在促进了PVK到Eu3 的能量传递.     

一种适合于OLED电视电源应用的新型超级结MOSFET

提出了一种新型超级结MOSFET结构,通过优化Si表面漂移区的杂质分布以抑制器件的结型场效应管(JFET)效应,改善器件特性。首先通过技术计算机辅助设计(TCAD)模拟并对比了新型超级结MOSFET和现有超级结MOSFET的电场强度分布、栅漏耦合电容随漏极电压的变化和开关过程,发现600 V新型超级结MOSFET比现有600 V超级结MOSFET的击穿电压提高了15 V、比导通电阻减小约3%,开关特性得到了大幅改善,器件关断时漏极电压尖峰降低41 V,栅极电压尖峰降低10 V。该新型超级结MOSFET在国内晶圆制造平台上成功制作,获得了优异的器件性能。在300 W有机发光二极管(OLED)电视电源板上进行替代纵向双扩散MOSFET(VDMOSFET)的对比测试,发现电源系统使用该新型超级结MOSFET比使用现有超级结MOSFET,其电磁干扰(EMI)性能改善了4.32～5.8 dB;与使用VDMOSFET相比,在保持EMI性能同等水平的同时,系统效率提高了0.52%。     

用BPhen作基质的铕配合物OLED发光机制研究

用具有良好电子传输/空穴阻挡性能的BPhen(4,7-diphenyl-1,10-phenanthroline)作基质,Eu(DBM)3pyzphen(pyzphen=pyrazino-[2,3-f][1,10]-phenanthroline,DBM=Dibenzoylmethane)作发射材料,成功制得了高效率、高亮度的有机电致发光器件OLED.器件的最大外量子效率为2.5%,最大电流效率为5.3 cd/A,最大亮度为1 320 cd/m2.在亮度为200和1 000 cd/m2时,器件的色坐标分别为(0.66,0.33)和(0.65,0.34).深入研究了该器件的发光机制,发现在电致发光(EL)过程中,载流子直接被Eu(DBM)3pyzphen陷获是主要的发光机制,同时在BPhen与Eu(DBM)3pyzphen间还存在着有效的能量传递.     

基于Re(Ⅰ)配合物有机电致发光器件的研究进展

Re(Ⅰ)配合物能够产生较好的自旋轨道耦合,其内量子效率在理论上可以达到100%,比荧光材料高3倍。因其具有相对短的激发态寿命、室温下高的磷光量子效率、较好的热稳定性和化学稳定性等优点使其被广泛关注。文章对Re(Ⅰ)配合物在有机电致发光器件中的研究进展进行了综述,并对Re(Ⅰ)配合物分子设计与电致发光器件的发展前景进行了展望。     

利用Cu_2O(I)胶体铜的直接电镀工艺

概述了利用Cu_2O(I)胶体铜的非导体表面直接电镀工艺,适用于迅速、安全和经济地制造孔金属化印制板。     

Copper(I) Complex as Sensitizer Enables High-Performance Organic Light-Emitting Diodes with Very Low Efficiency Roll-Off

Organic light-emitting diodes (OLEDs) utilizing purely organic thermally activated delayed fluorescence (TADF) sensitizers have recently achieved high efficiencies and narrow-band emissions. However, these devices still face intractable challenges of severe efficiency roll-off at practical luminance and finite operational lifetime. Herein, a carbene-Cu(I)-amide complex, (MAC*)Cu(Cz), is demonstrated as a TADF sensitizer for both fluorescent and TADF OLEDs. The (MAC*)Cu(Cz)-sensitized fluorescent OLED not only achieves a high external quantum efficiency (EQE) of 14.6% with an extremely low efficiency roll-off of 12% at the high luminance of 10 000 nits, but also delivers a 15 times longer operational lifetime than that of the non-sensitized reference device. More importantly, utilizing the (MAC*)Cu(Cz) sensitizer in the multi-resonance (MR) TADF OLED results in a record-high EQE of 26.5% together with a full-width at half maximum of 46 nm and an emission peak at 566 nm. This value is the state-of-the-art efficiency for yellow-emitting MR-TADF OLEDs. The photophysical analysis proved that the fast reverse intersystem crossing process of (MAC*)Cu(Cz) is the key factor to suppress triplet exciton involved quenching at high luminance. This finding firstly demonstrates the use of Cu(I) complex as an efficient TADF sensitizer and paves the way for practical applications of TADF sensitized OLEDs.     

有机电荷产生层对叠层磷光OLED器件性能的影响

采用C60/pentanece作为非掺杂电荷产生层,并在其两边各插入Al和MoOs薄层作为C60和pentanece的电子注入层和空穴注入层,在此基础上制备了结构为ITO/NPB/mCP∶8wt％Ir (ppy) 3/TPBi/Al/C60/pentanece/MoOs/NPB/mCP∶8wt％Ir (ppy) 3/TPBi/Cs2CO3/Al的双发光单元叠层绿色磷光有机发光器件(OLED).实验表明,增加Al和MoO3电荷注入层,可有效改善有机电荷产生层的电荷注入能力,提高叠层OLED器件的发光亮度和电流效率.叠层器件的启亮电压明显低于单个器件的1/2,但电流效率是单层器件的两倍以上.当Al/C60/pentanece/MoO3的厚度分别是3、15、25和1 nm时,叠层OLED器件具有最佳的光电性能,其最大亮度和最大电流效率分别是7 920.0 cd/m2和16.4 cd/A.     

High efficiency organic light-emitting diodes with in situ synthesized Cu(I) complex emitter: How to do chemical reaction in a vacuum chamber?

Cu(I) complexes are considered as idea emitters in organic light-emitting diodes (OLEDs) due to their low cost and theoretical high internal quantum efficiency, which are two important issues have to be concerned for OLEDs commercialization. However, most Cu(I) complexes are unstable toward sublimation and hence not amenable to the vacuum deposition method typically used to fabricate OLEDs. To solve this problem, a codeposition route that involves codeposition of CuI and pyridine derivative has been proposed to synthesis Cu(I) complex emitter in situ. Since chemical reactions were conducted in a vacuum chamber, we systematically studied the effect of reactant chemical structure, reaction ratio, and deposition rate on the in situ synthesized Cu(I) complex and its application as an emitter in OLEDs. With an optimal chemical reaction condition, the device showed a high external quantum efficiency (EQE) up to 14.2% at a brightness of 100 cd/m², corresponding to a current and power efficiency of 45.2 cd/A and 33.3 lm/W, respectively. The performance is comparable to those efficient OLEDs with iridium complex emitter, while using a CuI dopant that having only one ten-thousandth of price to bis(2-phenylpyridine) (acetylacetonate)iridium.     

Copper (I) Selenocyanate (CuSeCN) as a Novel Hole‐Transport Layer for Transistors,Organic Solar Cells,and Light‐Emitting Diodes

The synthesis and characterization of copper (I) selenocyanate (CuSeCN) and its application as a solution‐processable hole‐transport layer (HTL) material in transistors, organic light‐emitting diodes, and solar cells are reported. Density‐functional theory calculations combined with X‐ray photoelectron spectroscopy are used to elucidate the electronic band structure, density of states, and microstructure of CuSeCN. Solution‐processed layers are found to be nanocrystalline and optically transparent (>94%), due to the large bandgap of ≥3.1 eV, with a valence band maximum located at ?5.1 eV. Hole‐transport analysis performed using field‐effect measurements confirms the p‐type character of CuSeCN yielding a hole mobility of 0.002 cm² V^?1 s^?1. When CuSeCN is incorporated as the HTL material in organic light‐emitting diodes and organic solar cells, the resulting devices exhibit comparable or improved performance to control devices based on commercially available poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate as the HTL. This is the first report on the semiconducting character of CuSeCN and it highlights the tremendous potential for further developments in the area of metal pseudohalides.     

双主体掺杂红色有机电致发光显示器件的研究

利用三源共蒸发技术制作了双主体掺杂红色有机电致发光显示器件,研究了不同掺杂比例下,Alq3∶Rubrene∶DCJTB双主体掺杂系统的红色OLED器件,器件结构为ITO/HIL/NPB/Alq3∶Rubrene∶DCJTB/Alq3/LiF/Al,其中发光层Alq3∶Rubren∶DCJTB是三掺杂发光结构体系。综合研究分析了Alq3与Rubrene的掺杂比例和发光效率、色纯度之间的关系,当Rubrene的掺杂比例达到60%时,器件达到最佳效果;电压9V时,该器件发光亮度达到3580cd/m2,发光效率达到4.58cd/A,功率效率也达到1.60lm/W,相应的色坐标为(0.65,0.35)。     

Rational Ligand Design of Heteroleptic Iridium (III) Complexes toward Nearly Perfect Horizontal Dipole Orientation for Highly Efficient Red-Emitting Phosphorescent Organic Light-Emitting Diodes

The horizontal orientation of the transition dipole moment of the phosphorescent emitters is understood to be an important factor to enhance the external quantum efficiency (EQE) of organic light-emitting diodes by improving light out-coupling in optical microcavity structures. Here, red-emitting heteroleptic iridium (III) complexes exhibiting an extremely high horizontal ratio of emitting dipole orientation (EDO) and photoluminescence quantum yield (PLQY), as well as longer device operational lifetime, without scarifying any other photophysical properties are reported. The systematic molecular design of main and ancillary ligands in heteroleptic iridium complexes leads to the achievement of both a horizontal EDO of 92% and a PLQY of 98% in the red-emitting phosphorescent devices along with a shorter exciton decay time of 0.71 µs. Accordingly, the red-emitting devices show excellent performances of maximum EQE of 32% and low-efficiency roll-off with the 1931 Commission Internationale de L′Eclariage coordinates of (0.66, 0.34). Therefore, this approach opens the way for further development of new red-emitting iridium complexes pushing the device efficiency toward the theoretical limits.     

BCP的厚度对OLED性能的影响

设计了一种有机电致发光器件（OLED）结构：ITO／NPB（50nm）／BCP（x）／Alq3（50mm）／LiF（0．5mm）／Al（120nm）。在实验中改变BCP的厚度,调整电子和空穴的注入平衡,控制发光层（EML）。研究发现：当BCP的厚度为0nm时,器件为典型的双层OLED结构,光谱为绿色的Alq3特征光谱;当厚度为8nm或8nm以上时,发光区完全基于NPB层,器件为蓝色发光;当厚度在1nm到8nm时,NPB层和Alq3层对发光都有贡献,EL谱线包括蓝光发射和绿光发射。BCP层起到了调节载流子复合区域和改变器件发光颜色的作用,因此控制BCP的厚度可以改善器件的性能。     

顶部发射绿色磷光OLED的制备与瞬态性能研究

用磷光材料Ir(ppy)3制备了高效率顶部发射绿色有机发光二极管(OLED),器件的结构为:ITO/Ag/NPB/Ir(ppy)3(5wt%):TPBI/TPBI/LiF/Al。研究发现与传统的无微腔结构器件相比顶部发射器件的性能有大幅度提高,其最大效率为18cd/A。通过使用F-P腔,器件的电致发光(EL)寿命由7.6μs降低为7.1μs,有效地缓解了效率随电流密度增大而下降的问题。顶部发射器件EL共振的主峰位于505nm处,发射光谱半峰宽(FWHM)窄化为23nm,色纯度为(x=0.122,y=0.671),发射光随探测角度变化较小。最后,分析了其瞬态光电性能变化原因。     

Origin of Hole-Trapping States in Solution-Processed Copper(I) Thiocyanate and Defect-Healing by I2 Doping

Solution-processed copper(I) thiocyanate (CuSCN) typically exhibits low crystallinity with short-range order; the defects result in a high density of trap states that limit the device's performance. Despite the extensive electronic applications of CuSCN, its defect properties are not understood in detail. Through X-ray absorption spectroscopy, pristine CuSCN prepared from the standard diethyl sulfide-based recipe is found to contain under-coordinated Cu atoms, pointing to the presence of SCN⁻ vacancies. A defect passivation strategy is introduced by adding solid I₂ to the processing solution. At small concentrations, the iodine is found to exist as I⁻ which can substitute for the missing SCN⁻ ligand, effectively healing the defective sites and restoring the coordination around Cu. Computational study results also verify this point. Applying I₂-doped CuSCN as a p-channel in thin-film transistors shows that the hole mobility increases by more than five times at the optimal doping concentration of 0.5 mol.%. Importantly, the on/off current ratio and the subthreshold characteristics also improve as the I₂ doping method leads to the defect-healing effect while avoiding the creation of detrimental impurity states. An analysis of the capacitance-voltage characteristics corroborates that the trap state density is reduced upon I₂ addition.     

Synthesis and characterization of blue-emitting Ir(III) complexes with multi-functional ancillary ligands for solution-processed phosphorescent organic light-emitting diodes

A series of Ir(III) complexes, (dfpmpy)₂Ir(pic), (dfpmpy)₂Ir(EO₂-pic), (dfpmpy)₂Ir(pic-N-O), and (dfpmpy)₂Ir(EO₂-pic-N-O), containing 2-(2,4-difluorophenyl)-4-methylpyridine (dfpmpy) based main ligand with varying ancillary ligands such as picolinic acid (pic), 4-(2-ethoxyethoxy)picolinic acid (EO₂-pic), picolinic acid N-oxide (pic-N-O), and 4-(2-ethoxyethoxy)picolinic acid N-oxide (EO₂-pic-N-O), respectively were successfully synthesized for highly efficient blue phosphorescent organic light-emitting diodes (PhOLEDs). The photophysical, electrochemical, and electroluminescent (EL) properties were systematically correlated. The solubilizing 2-ethoxyethanol (EO₂-) group was attached to the ancillary ligand through tandem reaction. All of the Ir(III) complexes show high thermal stability and good photoluminescence quantum yields (Ф_pl) in film state. Solution-processed PhOLEDs were fabricated using these Ir(III) complexes as dopants and achieved a maximum external quantum efficiency (EQE) of 10.9% and current efficiency of 21.15 cd/A for (dfpmpy)₂Ir(EO₂-pic). All the Ir(III) complexes emitted blue light with color purity at the Commission Internationale de L’Eclairage (CIE) coordinates of (0.15, 0.31).