有机薄膜发光器件的研究进展

有机薄膜电致发光器件具有发光效率高、驱动电压低、功耗小、响应速度快等优点,已成为近年来显示技术领域的研究热点.基于有机发光器件的能级结构,分析了电极、有机薄膜以及界面三者对器件性能的影响及相应的改进措施.重点介绍了有机发光材料的研究进展,简要介绍了国内外在有机电致发光显示方面的最新进展.     

薄膜a-Si PIN/OLED图像传感显示器的设计与模拟

设计了一种将薄膜a-SiPIN光敏传感单元与OLED有机发光显示单元合二为一的新型图像传感显示器件;通过对每个单元的分别建模以及叠层器件的串联结构特点,对器件单元像素的电流电压特性进行了模拟.结果表明:器件驱动电压的降低主要通过增大OLED的幂指数因子实现;薄膜a-Si PIN的灵敏度对器件灵敏度有决定性的影响;降低a-Si PIN隙态密度能有效地展宽器件的线性响应区域;器件应用领域的不同,对a-SiPIN的并联等效电阻的大小有不同的要求.     

薄膜a-Si PIN/OLED图像传感显示器的设计与模拟

设计了一种将薄膜a-SiPIN光敏传感单元与OLED有机发光显示单元合二为一的新型图像传感显示器件;通过对每个单元的分别建模以及叠层器件的串联结构特点,对器件单元像素的电流电压特性进行了模拟.结果表明:器件驱动电压的降低主要通过增大OLED的幂指数因子实现;薄膜a-Si PIN的灵敏度对器件灵敏度有决定性的影响;降低a-Si PIN隙态密度能有效地展宽器件的线性响应区域;器件应用领域的不同,对a-SiPIN的并联等效电阻的大小有不同的要求.     

热处理提高蓝色有机电致发光器件性能的研究

选取梯形次对苯基聚合物LPPP和小分子Ya二唑材料OXD－7分别作为具有空穴转移特性的发光层材料及电子输运材料制备了蓝色有机电致发光（OEL）器件,采用热处理方法显著地提高了其发光性能,其最佳热处理条件为：真空中,170℃,1h。初步分析了热处理提高器件发光性能的原因,主要有两个因素：高温作用促进异质结的形成;热处理改善器件阴极／有机薄膜界面的接触状况,有效地减少器件工作中产生的黑斑。     

有机-无机杂化钙钛矿激光器的研究进展

有机-无机杂化钙钛矿具有载流子扩散长度长、发光效率高等特点,是一种性能优良的半导体材料,也是一种极具潜力的激光增益介质,受到了光伏、激光等多个领域的广泛关注.概述了利用有机-无机杂化钙钛矿作为增益介质研发的薄膜型多晶钙钛矿激光器、单晶钙钛矿激光器以及微盘钙钛矿激光器的研究进展.介绍了具有优异的电学性能和光学性能的有机-无机杂化钙钛矿制备方法,分析了影响有机-无机杂化钙钛矿激光器性能的主要因素.结果表明,相对于其他类型的激光器,单晶钙钛矿纳米线结构具有更低的激光阈值、更窄的光谱宽度,是实现纳米激光的最佳选择之一.此外,针对有机-无机杂化钙钛矿激光器目前存在的钙钛矿材料的降解、实现电泵浦激光所需电流密度高等问题,对今后钙钛矿激光器的研究重点和发展趋势进行展望.     

有机发光显示技术及有机半导体

近年来有机发光显示技术及其应用的迅速发展,使人们对有机半导体材料和器件有了新的认识.有机半导体材料及器件是近期有望取得重大突破的一个十分活跃的研究领域.有机半导体材料有可能在有机电致发光、有机光电转化、有机场效应管、太阳能电池以及信息存贮器件等领域得到广泛应用,并将促进有机电子产业的进一步发展.     

有机发光显示技术及有机半导体

近年来有机发光显示技术及其应用的迅速发展,使人们对有机半导体材料和器件有了新的认识.有机半导体材料及器件是近期有望取得重大突破的一个十分活跃的研究领域.有机半导体材料有可能在有机电致发光、有机光电转化、有机场效应管、太阳能电池以及信息存贮器件等领域得到广泛应用,并将促进有机电子产业的进一步发展.     

磁性电极作为衬底的有机电致发光器件

有机电致发光器件(Organic Light-Emitting Device, OLED)已成为当今最热门的研究领域之一。以钛酸锶(100)作为基底, 采用RF磁控溅射镀膜系统制成磁性电极La1-xSrxMnO3(LSMO)薄膜, 为了增加钛酸锶基底LSMO薄膜的透光率, 对该基底进行了双面光学抛光。在此基础上, 以LSMO为衬底, 制作了结构为LSMO/NPB/Alq3/CsF/Mg:Ag的有机电致发光器件。器件大约在14 V时启亮, 在25 V时, 器件达到最大亮度。在磁场作用下, 研究了器件的亮度-电压-电流特性。在大约150 mT磁场下, 器件的发光亮度增大10%。研究结果表明: 由于经LSMO注入发光层内部的电子和空穴自旋方向被部分极化, 发光层单线态与三线态激子的形成比率增加。由于发光材料Alq3是单线态有机材料, 因而, 器件发光亮度增大。     

稀土有机配合物电致发光器件的研究进展

概述了稀土有机配合物电致发光薄膜器件的材料、结构、发光机理以及目前研究的状况、出现的问题和研究的发展趋势.     

掺分子多聚物的有机EL器件

有机薄膜 EL 器件有可能实现大屏幕显并因而受到人们的重视。对于此种材料,发光层内空穴与电子的复合激发了发光材料,因而产生 EL。Tang 等人首先报导了使用空穴输运层将空穴由电极注入到发光层内的方法,采用此种方法可将驱动电压降至几伏。这种器件是有机空穴输运层和发光电子     

Molecular Stacking Induced by Intermolecular C–H···N Hydrogen Bonds Leading to High Carrier Mobility in Vacuum‐Deposited Organic Films

Simple bottom‐up fabrication processes for molecular self‐assembly have been developed for the construction of higher‐order structures using organic materials, and have contributed to maximization of the potential of organic materials in chemical and bioengineering. However, their application to organic thin‐film devices such as organic light‐emitting diodes have not been widely considered because simple fabrication of a solid film containing an internal self‐assembly structure has been regarded as difficult. Here it is shown that the intermolecular C–H···N hydrogen bonds can be simply formed even in vacuum‐deposited organic films having flat interfaces. By designing the molecules containing pyridine rings properly for the intermolecular interaction, one can control the molecular stacking induced by the intermolecular hydrogen bonds. It is also demonstrated that the molecular stacking contributes to the high carrier mobility of the film. These findings provide new guidelines to improve the performance of organic optoelectronic devices and open up the possibilities for further development of organic devices with higher‐order structures.     

Diindenoperylene derivatives: A model to investigate the path from molecular structure via morphology to solar cell performance

Efficient organic electronic devices require a detailed understanding of the relation between molecular structure, thin film growth, and device performance, which is only partially understood at present. Here, we show that small changes in molecular structure of a donor absorber material lead to significant changes in the intermolecular arrangement within organic solar cells. For this purpose, phenyl rings and propyl side chains are fused to the diindenoperylene (DIP) molecule. Grazing incidence X-ray diffraction and variable angle spectroscopic ellipsometry turned out to be a powerful combination to gain detailed information about the thin film growth. Planar and bulk heterojunction solar cells with C60 as acceptor and the DIP derivatives as donor are fabricated to investigate the influence of film morphology on the device performance. Due to its planar structure, DIP is found to be highly crystalline in pristine and DIP:C60 blend films while its derivatives grow liquid-like crystalline. This indicates that the molecular arrangement is strongly disturbed by the steric hindrance induced by the phenyl rings. The high fill factor (FF) of more than 75% in planar heterojunction solar cells of the DIP derivatives indicates excellent charge transport in the pristine liquid-like crystalline absorber layers. However, bulk heterojunctions of these materials surprisingly result in a low FF of only 54% caused by a weak phase separation and thus poor charge carrier percolation paths due to the lower ordered thin film growth. In contrast, crystalline DIP:C60 heterojunctions lead to high FF of up to 65% as the crystalline growth induces better percolation for the charge carriers. However, the major drawback of this crystalline growth mode is the nearly upright standing orientation of the DIP molecules in both pristine and blend films. This arrangement results in low absorption and thus a photocurrent which is significantly lower than in the DIP derivative devices, where the liquid-like crystalline growth leads to a more horizontal molecular alignment. Our results underline the complexity of the molecular structure-device performance relation in organic semiconductor devices.     

有机薄膜器件电流机制的研究

对于有机薄膜器件(包括有机电致发光器件(OLED)和有机场效应晶体管(OTFT)),器件的电流机制直接决定了器件的性能,因此深刻理解其相关机理是十分必要的.虽然对于有机薄膜器件的电学性能研究较早,但是由于器件结构及有机薄膜内部影响机制的复杂性使得不同学者的研究结果很不一致.为此,文章以相同的镁银合金(MgAg)为电极,...     

真空气相沉积生长PTCDI C8 N型有机薄膜晶体管

在大气环境下N型有机薄膜晶体管(OFET)的性能不稳定,为提高晶体管在大气环境稳定性,该文分别制作了SiO2单绝缘层器件和SiO2/PMMA双绝缘层器件。采用N型新材料PTCDI-C8作为有源层,Ag作为源、漏电极,对制作的不同绝缘层的器件进行聚对二甲苯的封装,对有源层进行形貌和晶体结构分析。并进行电流-电压(I-V)曲线测试。在相同工作电压下,双绝缘层器件比单绝缘层器件具有更大的场效应迁移率、开关电流比和更小的阈值电压。     

有机/聚合物电致发光器件的稳定性问题

有机/聚合物电致发光(EL)器件走向实用化的最大障碍是其稳定性和寿命。文章综述了有机/聚合物EL器件的稳定性问题,并从器件的失效过程、电极材料及其界面对器件稳定性的影响及有机材料本身的稳定性等方面讨论了器件的稳定性。     

基于富勒烯类材料太阳能电池研究进展

从太阳能电池基本原理、新材料合成、活性层和修饰层的工艺改进、器件结构多样化以及电极材料的选取及工艺等方面介绍了基于富勒烯类材料的有机太阳能电池的研究进展,并探讨了今后有机薄膜器件研究的发展趋势。     

Distributed Feedback Lasers Based on Thiophene/Phenylene Co‐Oligomer Single Crystals

Organic crystals have great potential for the applications in laser devices. This article presents an effective approach for fabrication of distributed feedback single crystal lasers. With the laser interference ablation method, high quality grating structures have been fabricated on the organic single‐crystalline thin film materials. The relationship between the depth, periodicity, and laser fluence is discussed. The optical properties, such as photoluminescence, and diffractive properties are studied in detail. With the appropriate period, strong laser emission has been observed from these devices. Distributed feedback lasing is demonstrated from the laser interference ablated organic single crystals for the first time.     

有机电致发光器件中有机薄膜的制备方法

有机电致发光器件中有机薄膜的制备方法非常重要,不同方法制备的薄膜质量不同,这直接影响着器件的效率;制备方法直接影响到产业化中的器件制备成本。根据材料的不同,有机小分子常用真空蒸镀的方法,而高分子材料常用旋涂的方法制备薄膜。随着有机电致发光器件制备工艺的发展,相继出现了其他的制备工艺,如:有机蒸汽喷印(organic vapor jet printing)、有机气相沉积(organic vapor phase deposition)、丝网印刷(screen printing)和喷墨打印(ink jet printing)技术等,这对有机电致发光显示器产业化发展具有巨大的推动作用。文章综述了这些制备方法,比较了它们的优缺点,以及这些工艺对产业化的影响。     

Flexible Inorganic Ferroelectric Thin Films for Nonvolatile Memory Devices

Next‐generation wearable electronics call for flexible nonvolatile devices for ubiquitous data storage. Thus far, only organic ferroelectric materials have shown intrinsic flexibility and processability on plastic substrates. Here, it is shown that by controlling the heating rate, ferroelectric hafnia films can be grown on plastic substrates. The resulting highly flexible capacitor with a film thickness of 30 nm yields a remnant polarization of 10 µC cm^?2. Bending tests show that the film ferroelectricity can be retained under a bending radius below 8 mm with up to 1000 bending cycles. The excellent flexibility is due to the extremely thin hafnia film thickness. Using the ferroelectric film as a gate insulator, a low voltage nonvolatile vertical organic transistor is demonstrated on a plastic substrate with an extrapolated date retention time of up to 10 years.