喷墨印刷有机电致发光显示材料与器件进展

随着有机电致发光显示（OLED）技术的不断发展,OLED在智能手机、智能手表和电视等市场应用不断扩大。尤其是在小尺寸智能手机市场,OLED已成为主流的显示技术,并有望逐步替代LCD技术。但在中大尺寸显示产品如平板电脑、笔记本、显示器、电视等应用领域,受限于目前真空蒸镀工艺的高成本及可靠性问题,发展较为缓慢,但市场对其需求依然很高。相比于真空蒸镀技术,通过喷墨印刷技术制备显示器件,可极大地提高材料利用率,降低设备成本,且由于其是一种增材制造方式,可减少资源消耗和环境污染,更有利于实现大面积、轻、薄、柔的显示屏制造。本文介绍了用于喷墨印刷OLED的各功能层材料研究进展,并对印刷OLED器件结构、制备工艺及器件性能进行了讨论,最后对印刷OLED的发展前景进行了展望。     

喷墨打印镉基绿光量子点发光二极管及其界面

喷墨打印镉基量子点发光二极管(QLEDs)有望应用于大尺寸全彩显示面板且具有材料利用率高的特点而广受关注。但目前喷墨打印器件效率远低于旋涂制备的同结构器件,针对这一问题,本文研究了在PVK空穴传输层上喷墨打印绿光量子点器件及量子点墨水溶剂对传输层界面的影响。研究发现,喷墨打印过程中的层间互溶是影响器件效率的关键,在采用正交溶剂结合喷墨工艺优化实现了高质量的膜层与界面后,获得了6.3%的喷墨印刷绿光QLEDs外量子效率。     

用液晶驱动芯片驱动有机发光显示屏的设计

应用TFT液晶驱动芯片设计了一个TFT有机发光显示屏用的驱动电路。目前有机发光显示屏(OLED)是平板显示领域的研究热点,在研制长寿命、高稳定的器件方面取得了一定的进展,但与之配套的驱动电路还不是很成熟,而且专用芯片又价格昂贵。液晶显示器件的配套驱动芯片功能比较完善,且价格低廉,所以应用TFT液晶驱动芯片设计了TFT有机发光显示屏用的驱动电路很有实际意义。比较了TFT LCD与TFT OLED驱动原理的异同点,从原理上探讨了将TFT LCD用的驱动芯片加以改造,使其可用于驱动TFT OLED,并采用三星公司的TFT液晶驱动芯片S6C0655和S6C0671设计了一个驱动64×3×80的全彩色OLED显示屏的驱动电路。     

喷墨打印钙钛矿太阳能电池研究进展与展望

作为近年来光伏领域最具竞争力的材料之一,有机-无机杂化钙钛矿受到了广泛的关注.然而,由于薄膜制备手段的限制,工业化大面积生产钙钛矿太阳能电池仍处于起步阶段.喷墨打印技术是由家庭和办公室印刷发展而来的一种重要的工业制造技术,广泛应用于各种印刷电子行业.与其他沉积方法相比,它具有成本低、材料利用率高和图案化精度高等优势.作为一种直接书写技术,喷墨打印已经显示出了巨大的工业化潜力,并有望在钙钛矿太阳能电池产业化中获得应用.本文回顾了喷墨打印钙钛矿太阳能电池的发展进程,对喷墨打印技术应用到钙钛矿太阳能电池的各个功能层(电极、空穴传输层、电子传输层、钙钛矿活性层)的情况进行了总结,并分析了喷墨打印钙钛矿太阳能电池的现状.最后,讨论了现阶段喷墨打印钙钛矿太阳能电池所面临的挑战,并对未来喷墨打印技术在钙钛矿材料的商业化应用方面进行了展望.     

喷墨打印有机晶体管早期失效机理的光谱学研究

喷墨打印工艺是新兴的有机电子器件制造核心技术之一,而聚合有机半导体材料的选择从一定程度上决定了其可打印性和所制造器件的工作性能,因此变得极其重要。本文对PTAA(Polytriarylamine)这种聚合有机半导体材料进行了研究。用PTAA喷墨打印技术制备出了具有一定MOSFET器件特性的有机晶体管(OFET)并对其电学特性进行测试分析,利用红外光谱技术对PTAA材料在器件工作中所表现出的早期失效现象进行研究。     

基于拓展型特征金字塔的OLED像素缺陷检测方法

针对传统方式检测有机发光二极管（OLED）像素缺陷精度低以及成本高的问题,提出了一种基于拓展型特征金字塔网络（FPN）的喷墨打印OLED像素缺陷检测方法。首先对数据进行处理,获得喷墨打印OLED像素图像数据集,随后利用预训练模型ResNet18作为主干,选取其底层模块作为特征提取器,制定出更加适合打印像素缺陷的训练网络。通过将FPN进行拓展,使用具有丰富区域细节的大规模超分辨率特征来解耦像素缺陷检测,实现缺陷区域信息的获取与缺陷的像素级分割。实验中对比了不同方法在OLED像素数据集上的检测效果并评估了不同方法在几个缺陷类型上的性能。结果表明：所提出的方法对喷墨打印OLED像素缺陷的识别精度比直接使用FPN提升了5.5%（达到99.8%）,对缺陷区域的分割平均精度提升3.7%（达到88.8%）,且所提模型适用于小样本缺陷数据检测,具有研究价值和实践意义。     

掺杂型红色有机电致发光显示器件

全色显示是有机电致发光显示(OLED)器件发展的目标,而高性能红色发光器件一直是制约全彩色OLED器件实用化的瓶颈,也是目前有机电致发光显示研究的热点。制作了掺杂DCJTB和不同浓度的rubrene两种荧光染料的红色有机电致发光显示器件,以NPB和Alq₃分别作为空穴传输层和电子传输层,发现器件性能与只掺杂DCJTB的器件相比有明显提高,发光效率提高到2～3倍。通过Frster理论和能带理论分析了器件的能量转移机理,研究发现Frster能量转移不是掺杂器件能量转移的主要形式,载流子俘获机制才是器件效率提高的主要原因;rubrene的引入使得能量能够更有效地从Alq₃转移到DCJTB,从而显著地提高了器件的发光效率和性能。     

高分辨率量子点图案化技术

由于量子点优异的材料特性,包括可调的能带间隙、高量子产率、高稳定性和可低成本地溶液加工等,其在显示领域引发了浓厚的兴趣和研究热潮。近年来,随着全世界对高质量显示的需求日益增长,特别是随着虚拟/增强现实（VR/AR）等近眼显示技术的兴起,对高亮度、高分辨率、高效率以及低功耗的显示技术提出了更高的要求。本文全面探讨了高分辨率量子点图案化技术,深入解析它们的工艺流程,并详细阐述它们在量子点显示器件中的各种应用。此外,还概述了高分辨率量子点图案化技术在实际应用中所面临的主要挑战。我们认为,要将高分辨率量子点图案化技术真正地应用到实际设备中,必须全面考虑各种因素,不仅包括从图案化技术出发,同时还涉及到从材料选择和器件结构设计等多个角度的深入思考和策划。本综述可为高分辨率量子点图案化技术行业的发展和研究提供有价值的参考。     

梦幻般的显示技术

更新一代的照明和显示技术OLED是英文Organic Light Emitting Diode的缩写,即有机发光二极管,是指有机材料在电场作用下发光的技术。而LED所采用的是无极材料,OLED与LED的相同之处在于两者都可以用在显示和照明领域。不同的是,在照明领域,受结构限制,LED是点光源,而OLED是平面光源：在显示领域,LED显示屏是由发光二极管排列组成的显示器件。无法显示高分辨率的图像,而OLED是由光刻电极基板与有机发光材料结合组成的显示器件,     

基于NiosⅡ的OLED显示驱动技术研究

为了利用有机发光二极管(OLED)显示屏显示字符及图形,对基于Nios技术的OLED显示驱动进行了研究。利用FPGA开发环境编写SVGA时序的Verilog HDL程序,设计了适合EMA-100080型SVGA+主动矩阵OLED微型OLED显示屏的SVGA接口;利用Nios集成开发环境编写C语言程序/控制字符、图形的生成及传输,协调NiosⅡ和FPGA之间数据传输。经调试及验证,表明OLED屏能够显示特定的字符及图形。     

Multi-nozzle electrohydrodynamic inkjet printing of silver colloidal solution for the fabrication of electrically functional microstructures

In this paper, multi-nozzle electrohydrodynamic (EHD) inkjet printing of a colloidal solution containing silver nanoparticles in a fully controlled fashion is reported. For minimizing interaction, i.e. cross-talk, between neighboring jets, the distance between the nozzles was optimized numerically by investigating the magnitude of the electric field strength around the tip of each nozzle. A multi-nozzle EHD inkjet printing head consisting of three nozzles was fabricated and successfully tested by simultaneously printing electrically conductive lines of a colloidal solution containing silver nanoparticles onto a glass substrate. The printed results show electrical resistivity of 5.05×10⁻⁸ Ω m, which is almost three times larger than that of bulk silver. These conductive microtracks demonstrate the feasibility of the multi-nozzle EHD inkjet printing process for industrial fabrication of microelectronic devices.     

平板显示技术比较及研究进展

平板显示因具有体积小、重量轻、功耗低、画质好等优点,已被广泛应用于电子仪表显示、车载显示、数码相机、智能手机、个人电脑、电视产品等领域之中。本文介绍了薄膜晶体管液晶显示(Thin Film Transistor-Liquid Crystal Display,TFTLCD)、有机发光二极管Organic Light Emitting Diode(OLED)显示、量子点发光二极管Quantum Dot Light Emitting Diode(QLED)显示及微发光二极管(Micro-LED)显示这几种平板显示技术的结构及原理。从结构、材料、性能、应用几方面对这几种平板显示技术进行了比较。最后给出了这几种平板显示技术的最新研究进展。LCD显示经过多年发展,技术成熟,成本低廉,仍然在显示市场占据主流地位。OLED显示技术摆脱了传统LCD的背光源,开创了自发光显示的未来发展方向。在相当一段时期内,LCD和OLED仍将会共存于市场中,相互竞争和补充。QLED显示和Micro-LED显示这两种显示技术,在理论上较OLED显示具有更好的颜色表现、更长的工作寿命等优势,具有非常广阔的发展前景,将为未来显示行业提供更多更好的选择。     

典型有机发光二极管中载流子传输和复合模型

提高载流子复合效率是改善有机发光二极管(OLEDs)发光效率的重要方法。采用真空热蒸发成膜法制作了典型双层结构的OLEDs(ITO/TPD/Alq₃/Al)。二极管的性能测试结果表明器件的电流-电压关系与Fow ler-Nordheim场发射载流子注入理论符合得较好。以Fow ler-Nordheim场发射载流子的隧穿注入理论为基础,对OLEDs的电流进行理论分析和数学推导,建立典型双层结构有机发光二极管中载流子传输、复合的理论模型。以此模型为依据,对载流子注入复合进行理论分析,探究载流子注入复合的效率的表达式。在外加电压和器件材料一定下,得出了载流子复合效率与阳极区一侧积累的空穴面密度和阴极区一侧积累的电子面密度的关系表达式。     

Effects of nozzles array configuration on cross-talk in multi-nozzle electrohydrodynamic inkjet printing head

This paper presents the analysis of a triangular array of nozzles in a multi-nozzle electrohydrodynamic (EHD) inkjet printing head. A methodology has been proposed to minimize the “end effect” by changing the traditional linear array of nozzles to triangular array of nozzles in multi-nozzle EHD printing head. Interaction (cross-talk) between the electrically charged neighboring jets is investigated and analyzed both numerically and experimentally using three glass nozzles with independent voltage connections and independent ink supply to each nozzle. In order to scrutinize the performance of triangular array multi-nozzle EHD inkjet printing head, comparative study of triangular array multi-nozzle EHD inkjet printing head to the linear array multi-nozzle EHD inkjet printing head has been made on the basis of electric field simulations and experiments. Experimental results illustrate that in triangular array multi-nozzle EHD inkjet printing head, the over potential requirement is low and individual capillaries are operating with more independence as compared to linear array multi-nozzle EHD inkjet printing head.     

Fabrication and implementation of large-area organic light-emitting-diode devices on direct patterned backplanes

In this paper, we report on a new cost-effective fabrication technology for large-area organic light-emitting diode (OLED) devices that we have developed. We fabricated OLED lighting devices on a directly patterned backplane using a dry process without employing conventional photolithography patterning technology. The indium–tin-oxide (ITO) anode, metal cathode, insulator, and emissive organic layer patterns were all formed directly on the substrates during the sputtering and evaporation steps by using a shadow mask without using etching or lift-off methods. We fabricated and characterized green phosphorescent emission OLED devices with an emission area of 30 × 120 mm², based on backplanes formed by direct patterning technology. Application of direct patterning technology reduced the total number of processing steps to 4 from the 26 steps required by conventional photo-patterning technology, making it possible to reduce large-scale production cost. Although the process steps were reduced considerably, the typical characteristics were comparable to those of photo-patterned OLEDs. Furthermore, the lifetime of the OLEDs based on direct patterned backplane was observed to be 27,200 h, which is approximately 97% of the lifetime of conventionally patterned OLEDs.     

Investigation of driving waveform and resonance pressure in piezoelectric inkjet printing

In order to improve the processing throughput and printing quality of inkjet printing technology, the droplet stability and ejection speed need to be well controlled. This paper investigates the relationship between the driving waveform and resonance pressure of piezoelectric inkjet printers using computational simulation and experiments. The detailed pressure history under various driving conditions is obtained. Furthermore, the individual contribution of each waveform parameter is evaluated.     

Fully printed organic solar cells – a review of techniques,challenges and their solutions

The emergence of solar cells on flexible and bendable substrates has made the printing process a ubiquitous tool for the fabrication of these devices. The various printing techniques available now such as inkjet, screen and flexography offer cost- effectiveness, user-friendliness and suitability for mass production. While downscaling the fill factor and efficiency of organic solar cells. A multilayered structure, the combination of different printing techniques avails the variety of thickness and resolution required for each layer in the production of an organic solar cell. In this review article, we discuss the suitability of the inkjet and screen printing processes to produce organic solar cells. We also discuss various challenges involved in the fabrication of organic solar cells using these two techniques and the possible solutions for the same. We also provide an analogy that both processes share. Further, we consider future possibilities of combining these printing technologies to produce organic solar cells to improve device performance.     

有机发光二极管光取出技术研究进展

有机发光二极管(OLED)在通信、信息、显示和照明等领域均显现出巨大的商业应用前景,十几年来一直是光电信息领域的研究热点之一.但是,OLED的外量子效率远低于内量子效率,极大程度地制约了其发展和应用.本文主要介绍了多种有效提高器件效率的光取出技术,对微透镜、光子晶体结构、纳米图案和纳米多孔膜以及微腔技术等多种OLED修饰方法进行了回顾和讨论.在此基础上,对一些光取出技术的研究做了展望.     

Inkjet printed Cu(In,Ga)S<Subscript>2</Subscript> nanoparticles for low-cost solar cells

Cu(In,Ga)Se₂ (CIGSe) thin film solar cells were fabricated by direct inkjet printing of Cu(In,Ga)S₂ (CIGS) nanoparticles followed by rapid thermal annealing under selenium vapor. Inkjet printing is a low-cost, low-waste, and flexible patterning method which can be used for deposition of solution-based or nanoparticle-based CIGS films with high throughput. XRD and Raman spectra indicate that no secondary phase is formed in the as-deposited CIGS film since quaternary chalcopyrite nanoparticles are used as the base solution for printing. Besides, CIGSe films with various Cu/(In + Ga) ratios could be obtained by finely tuning the composition of CIGS nanoparticles contained in the ink, which was found to strongly influence the devices performance and film morphology. To date, this is the first successful fabrication of a solar device by inkjet printing of CIGS nanoparticles.     

打印技术制备表面增强拉曼散射活性基底的研究进展

表面增强拉曼散射(SERS)是一种先进的表面分析技术,可以极大提高吸附在金属表面或附近分子的拉曼散射信号。SERS技术由于其快速准确、灵敏度高、选择性好、样品制备要求低等特点,成为当前的研究热点,在化学、食品、生物、医疗等领域展现出重要的应用前景。而利用SERS技术作为一种常规分析和诊断工具面临的一个主要挑战是如何制备均匀、可重复、稳定的活性基底。打印技术操作简单、效率高、成本低,有助于设计等离激元纳米结构。通过优化“热点”增强电磁场,获得重复性好、稳定性高、增强能力强的SERS活性基底。近年来,印刷技术逐渐被应用于SERS基底的制备。主要综述了制备SERS基底的几种常用印刷技术,包括喷墨印刷、凹版印刷、丝网印刷等。分析了衬底表面润湿性、干燥温度、油墨粘度、表面张力、溶剂等因素对SERS性能的影响。总结了印刷技术制备SERS基底的研究进展,并对其潜在应用和未来发展作了展望。