Name: enhanced electron injection and exciton confinement for pure blue quantum-dot light-emitting diodes by introducing partially oxidized aluminum cathode
Uploaded: 2018-05-31T15:00:00.000+00:00
Duration: 10 min 41 s
Description: Watch this Scientific Journal Video about Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode at JoVE

这项工作得到国家自然科学基金 (51573042)、全国重点基础研究项目 (973 项目、2015CB932201)、中央大学基础研究经费 (JB2015RCJ02、2016YQ06、2016MS50、2016XS47) 的支持。

1. 氧化铟锡 (ITO) 玻璃的图案蚀刻
<ol><li>将大片 ITO 玻璃 (12 厘米 x 12 厘米) 切成15毫米宽的长条。使用带有酒精的无尘布清洁 ITO 玻璃表面。</li>
	<li>用数字万用表检查 ITO 玻璃的导电面。用胶带覆盖 ITO 玻璃的活动面积, 使活动面积在中间有2毫米宽。</li>
	<li>将锌粉倒入 ITO 玻璃上 (厚度约为0.5 毫米)。</li>
	<li>将盐酸溶液 (36 wt%) 倒入 ito 玻璃表面, 让 ito 玻璃完全浸泡在盐酸溶液中, 然后蚀刻十五年代。</li>
	<li>在腐蚀后倒入盐酸溶液, 然后立即用清水冲洗 ITO 玻璃。取下 ITO 玻璃上的胶带。</li>
</ol>2. 清洁 ITO 玻璃
<ol><li>将 ito 玻璃浸入含有丙酮溶液的培养皿中15分钟. 用棉球擦拭 ito 玻璃上的胶水。</li>
	<li>用玻璃切割机将 ITO 玻璃切成方形 (约15毫米 x 15 毫米)。</li>
	<li>油脂实验在洗涤剂水、自来水、去离子水、丙酮和异丙醇中依次进行15分钟的 ITO 玻璃。</li>
	<li>用氮气吹干 ITO 玻璃, 然后在150摄氏度的烤箱中烘干5分钟的空气气氛。</li>
	<li>将所清洗的 ITO 玻璃放入紫外线臭氧室, 治疗15分钟。</li>
</ol>3. 孔注射层的制作
<ol><li>从冰箱中取出聚 (34-ethylenedioxythiophene):p oly (苯乙烯磺酸) (PEDOT: PSS) 溶液。搅拌 PEDOT: 室温下的 PSS 溶液为20分钟, 以获得均匀分散的溶液。 注: 紫外线臭氧治疗 (2.5 节) 和 PEDOT 的鼓动: PSS 解决方案应同时进行, 以避免紫外线臭氧治疗失败。室温保持在摄氏25摄氏度。</li>
	<li>取约2毫升的 PEDOT: PSS 溶液与10毫升注射器, 并在注射器上安装0.45 µm 聚醚砜 (PES) 过滤器。</li>
	<li>将 ITO 玻璃放在旋转涂布机的中心。在 ITO 玻璃上倒入两滴 PEDOT: PSS 溶液。</li>
	<li>自旋涂层过滤后的 PEDOT: 在 ITO 基体上的 pss 溶液在 3000 rpm 三十年代, 然后退火的 PEDOT: pss 涂层 ITO 在150°c 15 分钟, 给 30 nm PEDOT: PSS 薄膜。</li>
</ol>4. 孔传输层的制作
注: 孔输送层和发射层是在氮气填充手套箱中制造的, 其控制氧和水浓度低于 50 ppm。
<ol><li>在邻二氯苯 (1 毫升) 中溶解聚 (n, N′-双 (4-丁基苯基) N, N′-双 (苯基)-联苯胺) (聚 TPD), 浓度为25毫克mL-1。在室温下在充满氮气的手套盒中搅拌。</li>
	<li>将35µL 的聚 TPD 溶液倒入 PEDOT 上: PSS 涂层 ITO。自旋涂层的聚 TPD 解决方案在 3000 rpm 三十年代, 给 40 nm 多 TPD 薄膜, 然后退火150摄氏度30分钟。</li>
</ol>5. 发射层的制作
<ol><li>在甲苯溶液中溶解 ZnCdS/ZnS 量子点 (300 µL), 浓度为14.3 毫克 mL-1。</li>
	<li>将 ZnCdS/ZnS 溶液的35µL 倒入聚 TPD 的顶部。自旋涂层的 ZnCdS/ZnS 解决方案在 3000 rpm 三十年代, 给40纳米薄膜。 注: 烘烤是不必要的。</li>
</ol>6. 真空沉积
<ol><li>在达到 10-4 Pa 的压力后, 将铝 (8-Hydroxyquinolinate) (Alq3) 的基板沉积在热蒸发室中, 其速率为0.3 Å s-1 , 以提供 15 nm Alq3胶片。 注: Alq3仅存用于 ITO/PEDOT 的设备结构: PSS/聚 TPD/QDs/Alq3/Al。</li>
	<li>刮一个2毫米宽活性层与刮刀暴露 ITO 玻璃基板。</li>
	<li>将基板置于金属掩模中, 并将其转移到热蒸发室中。将铝电极存入1Å的-1 , 以提供100纳米铝膜。</li>
</ol>7. 氧化程序
<ol><li>将准备好的铝阴极转移到真空烤箱中, 然后将空气从烤箱中抽出, 直到几乎变成真空。</li>
	<li>打开通货紧缩阀, 注入无水复合空气 (O2= 20%, N2= 80%) 进入真空烘箱, 压力为 3 x 104宾夕法尼亚州在室温下 (在烤箱中) 氧化0、4.5、12和 17 h。</li>
</ol>

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蓝色发光二极管的器件结构由 ITO 透明阳极组成, PEDOT: PSS HIL (30 nm), 聚 TPD HTL (40 nm), ZnCdS/ZnS QDs EML (40 nm) 和 al: 铝2O3阴极 (100 nm)。由于铝阴极的多孔特性, 通过将其暴露于氧气中, 得到了氧化铝阴极。图 2e和图 2f显示了 QDs 层与 al 和 al 的能级对齐图: al2O3。当 QDs 接触铝阴极时, 在 QDs/铝接口上形成肖特基接触, 该界面引入了?...

基于胶体半导体量子点的发光二极管 (led) 由于其独特的优点, 包括溶液的加工性、可调谐的发射波长、优良的色泽纯度、柔性制造和低处理成本1,2,3,4。自1994年首次演示基于 QDs 的 led 指示灯以来, 为工程材料和设备结构5,6,7, 付出了巨大的努力。一个典型的半导体发光二极管装置设计为具有一个三层夹层结构, 由孔传输层 (HTL)、发射层和电子传输层 (ETL) 组成。选择合适的电荷传输层对于平衡注入孔和电子到发射层进行辐射重组至关重要。目前, 真空沉积小分子被广泛用作 ETL, 例如, bathocuproine (BCP)、三 (8-Hydroxyquinolinate) (Alq3) 和 3-(联苯-4-基)-5-(4-tertbutylphenyl)-4-苯基-4 h-12, 4-三唑 (狂暴)8。然而, 不平衡的载波注入往往会导致重组区域向 ETL 转移, 造成不必要的寄生电致发光 (EL) 发射并使设备性能恶化9。
为了提高器件的效率和环境稳定性, 将溶液处理的 ZnO 纳米粒子作为电子传输层, 而不是真空沉积的小分子材料。在传统设备体系结构中显示了高亮度的 RGB 发光二极管, 显示了3.1万、6.8万和 4200 cd m-2的亮度, 分别为橙色-红色、绿色和蓝色,10。对于反向设备体系结构, 成功地用亮度和外部量子效率 (EQE) 23040 个 cd m-2和7.3% 为红色、218800个 cd m-2和5.8% 实现了高性能的 RGB 发光二极管--低匝电压。绿色, 2250 个 cd m-2和1.7% 为蓝色, 分别为11。为了平衡注入的电荷并保持 QDs 发射层, 在 QDs 和 ZnO ETL 之间插入了一个绝缘聚 (methylmethacrylate) (PMMA) 薄膜。最优化的深红色的发光二极管显示了高的外部量子效率高达20.5% 和低的打开电压只有 1.7 V12。
此外, 优化 QDs 的光电性能和纳米结构也对提高器件性能起着至关重要的作用。例如, 通过优化 ZnS 炮击时间13, 合成了具有光致发光量子产量 (PLQE) 98% 的高荧光蓝 QDs。同样, 通过精确控制反应温度, 合成了近 100% PLQE 的优质紫蓝色 QDs。紫蓝色 QDs LED 设备显示显着的亮度和 EQE 高达 4200 cd m-2和 3.8%, 分别为14。这种合成方法也适用于紫 ZnSe/ZnS 芯/壳 QDs, 该发光二极管显示高亮度 (2632 cd m-2) 和效率 (EQE = 7.83%) 使用无 cd QDs15。由于高 PLQE 的蓝色量子点已经被证明, QDs 层中的高电荷注入效率在制造高性能的光 led 发光二极管中扮演了另一个关键的角色。采用长链油酸配体, 以缩短 1-octanethiol 配体, QDs 膜的电子流动性增加了两倍, 并获得了高 EQE 值10% 以上的16。表面配体交换也可以改善 QDs 膜的形貌, 抑制 QDs 中的光致发光淬火。例如, 使用化学接枝 QDs-半导体聚合物混合器17, QDs LED 显示了改进的器件性能。此外, 由于增强的电荷注入、传输和重组18, 通过合理优化 QDs 壳的分级组成和厚度, 制备出高性能 QDs。
在这项工作中, 我们介绍了一个部分 autoxidized 铝 (Al) 阴极, 以提高性能的 ZnCdS/ZnS 分级核/壳型蓝光-led19。利用紫外光电子能谱 (UPS) 和 X 射线光电子能谱 (XPS) 验证了铝阴极势能屏障的变化。此外, 通过时间分辨光致发光 (TRPL) 测量, 分析了 QDs/al 和 QDs/al 的快速电荷载波动力学: al2O3接口。为了进一步验证部分氧化铝对器件性能的影响, 带不同阴极的发光二极管 (al, 铝: 铝2O3, al2o3/铝, al2o3/铝: al2o3, 和Alq3/Al) 是捏造的。因此, 采用 al2O3阴极, 以最大亮度为13002个 cd m-2 , 并以 1.15 cd a-1的峰值电流效率来演示高性能纯蓝色发光二极管。此外, 在设备体系结构中没有额外的有机 ETL, 可以避免不需要的寄生 EL, 以保证不同工作电压下的颜色纯度。

<table><tbody><tr><td>Indium Tin Oxide (ITO)-coated glass&lt;br/&gt; substrate</td><td>CSG Holding Co., Ltd.</td><td></td><td>Resistivity&amp;asymp;10 &amp;Omega;/sq</td></tr><tr><td>Zinc powder</td><td>Sigma-Aldrich</td><td>96454</td><td>Molecular Weight 65.38</td></tr><tr><td>Isopropyl alcohol</td><td>Beijing Chemical Reagent</td><td>67-63-0</td><td>Analytically pure</td></tr><tr><td>Toluene</td><td>Innochem</td><td>I01367</td><td>Analytically pure</td></tr><tr><td>Acetone</td><td>Innochem</td><td>I01366</td><td>Analytically pure</td></tr><tr><td>Hydrochloric acid</td><td>acros</td><td>124210025</td><td>1 N standard solution</td></tr><tr><td>O-dichlorobenzene</td><td>acros</td><td>396961000</td><td>98+%, Extra Dry</td></tr><tr><td>Poly(3,4-ethylenedioxythiophene) doped polystyrene sulfonate (PEDOT:PSS)</td><td>H. C.Stark</td><td>Clevious P VP Al 4083</td><td></td></tr><tr><td>Poly(N,N&amp;prime;-bis(4-butylphenyl)-N,N&amp;prime;-bis(phenyl)-benzidine) (Poly-TPD)</td><td>Luminescence Technology</td><td>LT-N149</td><td></td></tr><tr><td>Aluminum tris(8-Hydroxyquinolinate) (Alq&lt;sub&gt;3&lt;/sub&gt;)</td><td>Luminescence Technology</td><td>LT-E401</td><td></td></tr><tr><td>UV-O cleaner</td><td>Jelight Company</td><td>92618</td><td></td></tr><tr><td>Filter</td><td>Jinteng</td><td>JTSF0303/0304</td><td>Polyether sulfone (0.45 &amp;mu;m)</td></tr><tr><td>Ultrasonic cleaner</td><td>HECHUANG ULTRASONIC</td><td>KH-500DE</td><td></td></tr><tr><td>Digital multimeter</td><td>UNI-T</td><td>UT39A</td><td></td></tr><tr><td>Spin coater</td><td>IMECAS</td><td>KW-4A</td><td></td></tr><tr><td>Digital hotplate</td><td>Stuart</td><td>SD160</td><td></td></tr></tbody></table>

enhanced electron injection and exciton confinement for pure blue quantum-dot light-emitting diodes by introducing partially oxidized aluminum cathode

稳定高效的红色 (R)、绿色 (G) 和蓝色 (B) 基于解决方案处理的量子点 (QDs) 的光源在下一代显示器和固态照明技术中起着重要的作用。基于蓝色 QDs 的发光二极管 (led) 的亮度和效率仍然不如它们的红色和绿色对应, 这是由于不同颜色的光本身所不赞同的能量水平。为了解决这些问题, 应设计一种设备结构, 以平衡注入孔和电子到发射的量子点层。在这里, 通过一个简单的氧化策略, 展示了高亮度和高效率的纯蓝色发光二极管, 具有 ITO/PEDOT 结构: PSS/聚 TPD/QDs/al: 铝2O3。autoxidized al2O3阴极可以有效地平衡注入电荷, 并在不引入附加电子传输层 (ETL) 的情况下增强辐射重组。因此, 高颜色饱和的蓝色发光二极管的最大亮度达到1.3万个 cd m-2, 最大电流效率为 1.15 cd a-1。易于控制的氧化程序为实现高性能的蓝色亮灯 led 铺平了道路。

采用紫外-可见光吸收和光致发光 (PL) 光谱记录 ZnCdS/ZnS 分级核/壳型蓝 QDs 的光学特性. 采集透射电镜 (TEM) 和扫描电镜 (SEM) 图像, 为QDs 的形貌 (图 1)。采用 X 射线光电子能谱 (XPS)、电化学研究和紫外光电子能谱 (UPS) 检测 QDs 的结构特性和能级 (图 2)。时间分辨光致发光 (TRPL) 测量用于检测 QDs/al 和 QDs/al 之间的接口上的快速电荷载?...

Watch this Scientific Journal Video about Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode at JoVE

Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

提出了一种利用 autoxidized 铝阴极制备高性能、纯蓝色 ZnCdS/ZnS 基量子点发光二极管的协议。

采用部分氧化铝阴极增强电子注入和激子约束的纯蓝色量子点发光二极管

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation ...

enhanced-electron-injection-exciton-confinement-for-pure-blue-quantum

Research

Education

JoVE Core

JoVE Journal

Electrical Engineering

Engineering

Unit 1

Diodes

SCIENTISTS IN ACTION

8.7K 次观看.  North China Electric Power University. 提出了一种利用 autoxidized 铝阴极制备高性能、纯蓝色 ZnCdS/ZnS 基量子点发光二极管的协议。

视频: Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

Compact Quantum Dots for Single-molecule Imaging

Single-molecule imaging is an important tool for understanding the mechanisms of biomolecular function and for visualizing the spatial and temporal heterogeneity of molecular behaviors that underlie cellular biology 1-4. To image an individual molecule of interest, it is typically conjugated to a fluorescent tag (dye, protein, bead, or quantum dot) and observed with epifluorescence or total internal reflection fluorescence (TIRF) microscopy. While dyes and fluorescent proteins have been the mainstay of fluorescence imaging for decades, their fluorescence is unstable under high photon fluxes necessary to observe individual molecules, yielding only a few seconds of observation before complete loss of signal. Latex beads and dye-labeled beads provide improved signal stability but at the expense of drastically larger hydrodynamic size, which can deleteriously alter the diffusion and behavior of the molecule under study.
Quantum dots (QDs) offer a balance between these two problematic regimes. These nanoparticles are composed of semiconductor materials and can be engineered with a hydrodynamically compact size with exceptional resistance to photodegradation 5. Thus in recent years QDs have been instrumental in enabling long-term observation of complex macromolecular behavior on the single molecule level. However these particles have still been found to exhibit impaired diffusion in crowded molecular environments such as the cellular cytoplasm and the neuronal synaptic cleft, where their sizes are still too large 4,6,7.
Recently we have engineered the cores and surface coatings of QDs for minimized hydrodynamic size, while balancing offsets to colloidal stability, photostability, brightness, and nonspecific binding that have hindered the utility of compact QDs in the past 8,9. The goal of this article is to demonstrate the synthesis, modification, and characterization of these optimized nanocrystals, composed of an alloyed HgxCd1-xSe core coated with an insulating CdyZn1-yS shell, further coated with a multidentate polymer ligand modified with short polyethylene glycol (PEG) chains (Figure 1). Compared with conventional CdSe nanocrystals, HgxCd1-xSe alloys offer greater quantum yields of fluorescence, fluorescence at red and near-infrared wavelengths for enhanced signal-to-noise in cells, and excitation at non-cytotoxic visible wavelengths. Multidentate polymer coatings bind to the nanocrystal surface in a closed and flat conformation to minimize hydrodynamic size, and PEG neutralizes the surface charge to minimize nonspecific binding to cells and biomolecules. The end result is a brightly fluorescent nanocrystal with emission between 550-800 nm and a total hydrodynamic size near 12 nm. This is in the same size range as many soluble globular proteins in cells, and substantially smaller than conventional PEGylated QDs (25-35 nm).

We describe the preparation of colloidal quantum dots with minimized hydrodynamic size for single-molecule fluorescence imaging. Compared to conventional quantum dots, these nanoparticles are similar in size to globular proteins and are optimized for single-molecule brightness, stability against photodegradation, and resistance to nonspecific binding to proteins and cells.

紧凑型量子点的单分子成像

Single-molecule imaging is an important tool for  understanding the mechanisms of biomolecular function and for visualizing the  spatial and temporal ...

科研

工程学

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots

A quantum computer is a computer composed of quantum bits (qubits) that takes advantage of quantum effects, such as superposition of states and entanglement, to solve certain problems exponentially faster than with the best known algorithms on a classical computer. Gate-defined lateral quantum dots on GaAs/AlGaAs are one of many avenues explored for the implementation of a qubit. When properly fabricated, such a device is able to trap a small number of electrons in a certain region of space. The spin states of these electrons can then be used to implement the logical 0 and 1 of the quantum bit. Given the nanometer scale of these quantum dots, cleanroom facilities offering specialized equipment- such as scanning electron microscopes and e-beam evaporators- are required for their fabrication. Great care must be taken throughout the fabrication process to maintain cleanliness of the sample surface and to avoid damaging the fragile gates of the structure. This paper presents the detailed fabrication protocol of gate-defined lateral quantum dots from the wafer to a working device. Characterization methods and representative results are also briefly discussed. Although this paper concentrates on double quantum dots, the fabrication process remains the same for single or triple dots or even arrays of quantum dots. Moreover, the protocol can be adapted to fabricate lateral quantum dots on other substrates, such as Si/SiGe.

This paper presents a detailed fabrication protocol for gate-defined semiconductor lateral quantum dots on gallium arsenide heterostructures. These nanoscale devices are used to trap few electrons for use as quantum bits in quantum information processing or for other mesoscopic experiments such as coherent conductance measurements.

纳米加工门定义的GaAs / AlGaAs多量子点横向

A quantum computer is a computer composed of quantum bits (qubits) that takes advantage of quantum effects, such as superposition of states and ...

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by quantum mechanical effects such as tunneling through single dopants, scattering via interface defects, and discrete trap charge states. However, progress in silicon technology has shown that these phenomena can be harnessed and exploited for a new class of quantum-based electronics. Among others, multi-layer-gated silicon metal-oxide-semiconductor (MOS) technology can be used to control single charge or spin confined in electrostatically-defined quantum dots (QD). These QD-based devices are an excellent platform for quantum computing applications and, recently, it has been demonstrated that they can also be used as single-electron pumps, which are accurate sources of quantized current for metrological purposes. Here, we discuss in detail the fabrication protocol for silicon MOS QDs which is relevant to both quantum computing and quantum metrology applications. Moreover, we describe characterization methods to test the integrity of the devices after fabrication. Finally, we give a brief description of the measurement set-up used for charge pumping experiments and show representative results of electric current quantization.

The fabrication process and experimental characterization techniques relevant to single-electron pumps based on silicon metal-oxide-semiconductor quantum dots are discussed.

硅金属 - 氧化物 - 半导体量子点单电子泵

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by ...

Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors

Nitride and oxynitride (Sialon) phosphors are good candidates for the ultraviolet and visible emission applications. High performance, good stability and flexibility of their emission properties can be achieved by controlling their composition and dopants. However, a lot of work is still required to improve their properties and to reduce the production cost. A possible approach is to correlate the luminescence properties of the Sialon particles with their local structural and chemical environment in order to optimize their growth parameters and find novel phosphors. For such a purpose, the low-voltage cathodoluminescence (CL) microscopy is a powerful technique. The use of electron as an excitation source allows detecting most of the luminescence centers, revealing their luminescence distribution spatially and in depth, directly comparing CL results with the other electron-based techniques, and investigating the stability of their luminescence properties under stress. Such advantages for phosphors characterization will be highlighted through examples of investigation on several Sialon phosphors by low-energy CL.

Low-energy Cathodoluminescence for OxyNitride Phosphors

An excellent chemical and luminescence stabilities of (oxy)nitride phosphors present it as an promising alternative to currently used sulfide and oxide phosphors. In this paper, we present the way to investigate its local luminescence properties using low-energy cathodoluminescence (CL).

低能量的阴极射线（氧）氮化物荧光粉

Nitride and oxynitride (Sialon) phosphors are good candidates for the ultraviolet and visible emission applications. High performance, good stability and ...

化学

Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active layer which consists of blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and &#960;-conjugated triphenylamine molecules. This white light emission originates from exciplexes formed between PFD and amines in electronically excited states. A device containing PFD, 4,4&#39;,4&#39;&#39;-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA), Poly(ethylene oxide) and K2CF3SO3 showed white light emission with Commission internationale de l&#39;&#233;clairage (CIE) coordinates of (0.33, 0.43) and a Color Rendering Index (CRI) of Ra = 73 at an applied voltage of 3.5 V. Constant voltage measurements showed that the CIE coordinates of (0.27, 0.37), Ra of 67, and the emission color observed immediately after application of a voltage of 5 V were nearly unchanged and stable after 300 sec.

The authors present a method for fabricating stable white-light-emitting electrochemical cells utilizing emission from exciplexes formed between a blue-emitting fluorene polymer and aromatic amines.

白的制造发光电化学细胞与来自激发络合物稳定的发射

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active ...

Scale-up Chemical Synthesis of Thermally-activated Delayed Fluorescence Emitters Based on the Dibenzothiophene-S,S-Dioxide Core

We report a procedure to linearly scale-up the synthesis of 2,8-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)dibenzothiophene-S,S-dioxide (compound 4) and 2,8-bis(10H-phenothiazin-10-yl)dibenzothiophene-S,S-dioxide (compound 5) using Buchwald-Hartwig cross-coupling reaction conditions. In addition, we demonstrate a scaled-up synthesis of all non-commercially available starting materials that are required for the amination cross-coupling reaction. In the present article, we provide the detailed synthetic procedures for all of the described compounds, alongside their spectral characterization. This work shows the possibility to produce organic molecules for optoelectronic applications on a large scale, which facilitates their implementation into real world devices.

Scale-up synthesis of highly efficient thermally activated delayed fluorescence emitters is described in the presented article.

基于吩 s-二氧化硫核的热活化延迟荧光发射器的放大化学合成

We report a procedure to linearly scale-up the synthesis of 2,8-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)dibenzothiophene-S,S-dioxide (compound 4) and ...

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables the acquisition of photoluminescence spectra covering the time regime from nanoseconds up to 0.1 s. This enables us to follow the changes in the intensity (decay) and emission of the spectra over time. Using this method, it is possible to study diverse photophysical phenomena, such as the emission of phosphorescence, and the contributions of prompt and delayed fluorescence in molecules showing thermally activated delayed fluorescence (TADF). Remarkably, all spectra and decays are obtained in a single experiment. This can be done for solids (thin film, powder, crystal) and liquid samples, where the only limitations are the spectral sensitivity of the camera and the excitation wavelength (532 nm, 355 nm, 337 nm, and 266 nm). This technique is, thus, very important when investigating the excited state dynamics in organic emitters for their application in organic light-emitting diodes and other areas where triplet harvesting is of paramount importance. Since triplet states are strongly quenched by oxygen, emitters with efficient TADF luminescence, or those showing room temperature phosphorescence (RTP), must be correctly prepared in order to remove any dissolved oxygen from solutions and films. Otherwise, no long-lived emission will be observed. The method of degassing solid samples as presented in this work is basic and simple, but the degassing of liquid samples creates additional difficulties and is particularly interesting. A method of minimizing solvent loss and changing the sample concentration, while still enabling to remove oxygen in a very efficient and a repeatable manner, is presented in this work.

Here, we present a method of the spectroscopic characterization of organic molecules by means of time-resolved photoluminescence spectroscopy on the nanosecond-to-millisecond timescale in oxygen-free conditions. Methods to efficiently remove oxygen from the samples and, thus, limit luminescence quenching are also described.

利用 iccd 摄像机对无氧环境下的三重收集有机化合物进行光物理表征

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables ...

Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection

The ability to perform simultaneous resonant excitation and fluorescence detection is important for quantum optical measurements of quantum dots (QDs). Resonant excitation without fluorescence detection &#8211; for example, a differential transmission measurement &#8211; can determine some properties of the emitting system, but does not allow applications or measurements based on the emitted photons. For example, the measurement of photon correlations, observation of the Mollow triplet, and realization of single photon sources all require collection of the fluorescence. Incoherent excitation with fluorescence detection &#8211; for example, above band-gap excitation &#8211; can be used to create single photon sources, but the disturbance of the environment due to the excitation reduces the indistinguishability of the photons. Single photon sources based on QDs will have to be resonantly excited to have high photon indistinguishability, and simultaneous collection of the photons will be necessary to make use of them. We demonstrate a method to resonantly excite a single QD embedded in a planar cavity by coupling the excitation beam into this cavity from the cleaved face of the sample while collecting the fluorescence along the sample&#39;s surface normal direction. By carefully matching the excitation beam to the waveguide mode of the cavity, the excitation light can couple into the cavity and interact with the QD. The scattered photons can couple to the Fabry-Perot mode of the cavity and escape in the surface normal direction. This method allows complete freedom in the detection polarization, but the excitation polarization is restricted by the propagation direction of the excitation beam. The fluorescence from the wetting layer provides a guide to align the collection path with respect to the excitation beam. The orthogonality of the excitation and detection modes enables resonant excitation of a single QD with negligible laser scattering background.

Resonant excitation of a single self-assembled quantum dot can be achieved using an excitation mode orthogonal to the fluorescence collection mode. We demonstrate a method using the waveguide and Fabry-Perot modes of a planar microcavity surrounding the quantum dots. The method allows complete freedom in the detection polarization.

用正交激励和检测方法研究平面腔内铟量子点的共振荧光

The ability to perform simultaneous resonant excitation and fluorescence detection is important for quantum optical measurements of quantum dots (QDs). ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.

A protocol for the production of simple structured organic light-emitting diodes (OLEDs) is presented.

真空沉积有机发光二极管的生产与表征

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...

Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation

In this work, we demonstrate a facile method for colloidal lead halide perovskite nanoplatelet synthesis (Chemical formula: L2[ABX3]n-1BX4, L: butylammonium and octylammonium, A: methylammonium or formamidinium, B: lead, X: bromide and iodide, n: number of [BX6]4- octahedral layers in the direction of nanoplatelet thickness) via ligand-assisted reprecipitation. Individual perovskite precursor solutions are prepared by dissolving each nanoplatelet constituent salt in N,N-dimethylformamide (DMF), which is a polar organic solvent, and then mixing in specific ratios for targeted nanoplatelet thickness and composition. Once the mixed precursor solution is dropped into nonpolar toluene, the abrupt change in the solubility induces the instantaneous crystallization of nanoplatelets with surface-bound alkylammonium halide ligands providing colloidal stability. Photoluminescence and absorption spectra reveal emissive and strongly quantum-confined features. X-ray diffraction and transmission electron microscopy confirm the two-dimensional structure of the nanoplatelets. Furthermore, we demonstrate that the band gap of perovskite nanoplatelets can be continuously tuned in the visible range by varying the stoichiometry of the halide ion(s). Lastly, we demonstrate the flexibility of the ligand-assisted reprecipitation method by introducing multiple species as surface-capping ligands. This methodology represents a simple procedure for preparing dispersions of emissive 2D colloidal semiconductors.

This work demonstrates facile room-temperature synthesis of colloidal quantum-confined lead halide perovskite nanoplatelets by ligand-assisted reprecipitation method. Synthesized nanoplatelets show spectrally narrow optical features and continuous spectral tunability throughout the visible range by varying the composition and thicknesses.