Ce travail a été partiellement financé par une subvention en aide pour la recherche scientifique (n ° 24225003). Ce travail a été soutenu financièrement par le Oil &amp; Energy Corporation JX Nippon.

1. Préparation des solutions de couche active <ol><li> Solution de la couche active pour les dispositifs de PFD amine dopée REMARQUE: Le PFD, 4,4 &#39;, 4&#39; &#39;- tris [2-naphtyle (phényl) amino] triphénylamine (2-TNATA), 9,9-diméthyl - N -di (1-naphtyl) -N&#39; - N , N &#39;-diphényl-9H-fluorène-2,7-diamine (DMFL-NPB), le poly (oxyde d&#39;éthylène) (PEO), ont été utilisés tels que reçus. Le trifluorométhanesulfonate de potassium (K 2 CF 3 SO 3) a été séché sous vide à 200 ° C pendant 1 heure avant utilisation. <ol><li> Pour les dispositifs ayant un VFI: rapport d&#39;amine de 1: 0,25, dissoudre 10 mg de PFD et 2,5 mg de l&#39;amine aromatique dans 1 ml de chloroforme et agiter pendant 1 heure à 40 ° C. Pour les personnes ayant une puissance surfacique: rapport d&#39;amine de 1: 1, en utilisant 10 mg de l&#39;amine aromatique. </li><li> Par ailleurs, dissoudre 10 mg de PEO dans 1 ml de cyclohexanone et remuer pendant 1 heure à 60 ° C, et dissoudre 2,5 mg de trifluorométhanesulfonate de potassium (KCF 3 SO 3) en 1ml de cyclohexanone et remuez pendant 1 heure à 40 ° C. </li><li> Ajouter 0,78 ml de la solution de PEO et de 0,147 ml de la solution KCF 3 SO 3 à la solution de puissance surfacique à l&#39; aide de micropipettes. Agiter la solution mélangée pendant 4 heures à 40 ° C. </li><li> Filtrer la solution mélangée à l&#39;aide d&#39;un filtre à membrane avant le revêtement par centrifugation. </li></ol></li><li> Solution de la couche active du dispositif de VFI non dopé <ol><li> Pour le dispositif de VFI non dopé, dissoudre 10 mg de PFD dans 1 ml de chloroforme et agiter pendant 1 heure à 40 ° C. Les étapes qui suivent sont les mêmes que celles décrites précédemment pour les amines dopées dans VFI 1.1.2 - 1.1.4. </li></ol></li></ol> 2. Fabrication d&#39;appareils LEC NOTE: Procédé de fabrication de dispositifs LEC est résumée à la figure 1. <ol><li> Ultrasons propres motifs oxyde d&#39;indium-étain (ITO) substrats de verre avec un détergent dilué, suivi par l&#39;eau ionisée, l&#39;acétone et le 2-propanol en utilisant unbain bureau à ultrasons (38 kHz) pendant 3 minutes pour chaque étape. Enfin, éliminer le solvant en utilisant un N 2 ventilateur. </li><li> Traiter les substrats avec UV / O3 pendant 3 minutes en utilisant un spectrophotomètre UV / O3 unité de traitement selon le protocole du fabricant. Effectuer le procédé de revêtement de la couche active sous une atmosphère inerte dans une boîte à gants. </li><li> Définir un substrat nettoyé sur la tête d&#39;une tournette. Distribuer environ 100 ul de la solution de la couche active à l&#39;aide d&#39;une micropipette. Spin le substrat comme suit: 800 rpm pendant 60 secondes, augmenter le taux à 1000 rpm plus de 3 sec, puis tourner à 1000 tours par minute pendant 10 secondes. L&#39;épaisseur de la couche active sera d&#39;environ 150 nm. </li><li> Sécher les substrats revêtus dans la boîte à gants du jour au lendemain. </li><li> Essuyez excès de polymère pour assurer une connexion d&#39;électrode appropriée et l&#39;encapsulation. </li><li> Placez les substrats sur un support d&#39;évaporation pour dépôt d&#39;aluminium. Charger le support dans la chambre d&#39;évaporation, et thermiquement déposer une couche de 100 nm d&#39;aluminiumà un taux d&#39;évaporation de 0,4 nm / sec à travers un masque inoxydable d&#39;évaporation en acier, qui dispose de 3 mm de large ouvertures pour déposer le compteur d&#39;aluminium électrodes. </li><li> Lorsque le dépôt est terminé, transférer les dispositifs à une boîte à gants sous atmosphère inerte. Appliquer un cordon de UV résine époxy durcissable sous la forme d&#39;un rectangle à l&#39;aide d&#39;un distributeur. Placez un couvercle en verre (15 mm x 12 mm x 0,7 mm d&#39;épaisseur) sur la résine pour encapsuler le dispositif (voir la figure 1). </li><li> Cure de la résine en utilisant un rayonnement UV (dose cumulative: 6000 mJ / cm 2, longueur d&#39; onde: 365 nm) à partir d&#39; une source de lumière LED-UV. </li></ol> 3. Caractérisation <ol><li> mesures JVL REMARQUE: La densité de courant (J) de haute tension (V) -luminance (L) (JVL) les caractéristiques et les coordonnées de la Commission Internationale de l&#39;Eclairage (CIE) a été mesurée au moyen d&#39;un détecteur photoélectrique spectrale équipé d&#39;une tension continue moniteur source de courant. Le système de mesure est commandé par unPC avec un logiciel de contrôle personnalisé pour l&#39;acquisition de données. Le système a été calibré protocole du fabricant suivant et les mesures ont été réalisées dans l&#39;obscurité sous un rideau noir. <ol><li> Connecter les bornes aux contacts de l&#39;appareil avec des pinces crocodiles. Placez l&#39;appareil sur la scène de mesure. </li><li> Exécutez le logiciel de commande pour l&#39;acquisition de données. Le système contrôle la tension appliquée et du courant au fil du temps et recueille les spectres d&#39;émission par le spectromètre à travers une fibre optique. </li></ol></li></ol>

<ol>
	<li>Pei, Q., Yu, G., Zhang, C., Yang, Y., Heeger, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer+light-emitting+electrochemical+cells.">Polymer light-emitting electrochemical cells.</a> Science. 269 (5227), 1086-1088 (1995).</li><li>Sun, Q., Li, Y., Pei, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer+light-emitting+electrochemical+cells+for+high-efficiency+low-voltage+electroluminescent+devices.">Polymer light-emitting electrochemical cells for high-efficiency low-voltage electroluminescent devices.</a> J. Disp. Technol. 3 (2), 211-224 (2007).</li><li>Meier, S. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-emitting+electrochemical+cells:+recent+progress+and+future+prospects.">Light-emitting electrochemical cells: recent progress and future prospects.</a> Mater. Today. 17 (5), 217-223 (2014).</li><li>Edman, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-component+light-emitting+electrochemical+cell+fabricated+from+cationic+polyfluorene:+Effect+of+film+morphology+on+device+performance.">Single-component light-emitting electrochemical cell fabricated from cationic polyfluorene: Effect of film morphology on device performance.</a> J. Appl. Phys. 98 (4), 044502 (2005).</li><li>Fang, J., Matyba, P., Edman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Design+and+Realization+of+Flexible,+Long-Lived+Light-Emitting+Electrochemical+Cells.">The Design and Realization of Flexible, Long-Lived Light-Emitting Electrochemical Cells.</a> Adv. Funct. Mater. 19 (16), 2671-2676 (2009).</li><li>Yu, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stabilizing+the+Dynamic+p&#8722;+i&#8722;+n+Junction+in+Polymer+Light-Emitting+Electrochemical+Cells.">Stabilizing the Dynamic p&#8722; i&#8722; n Junction in Polymer Light-Emitting Electrochemical Cells.</a> J. Phys. Chem. Lett. 2 (5), 367-372 (2011).</li><li>Sandstr&#246;m, A., Dam, H. F., Krebs, F. C., Edman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ambient+fabrication+of+flexible+and+large-area+organic+light-emitting+devices+using+slot-die+coating.">Ambient fabrication of flexible and large-area organic light-emitting devices using slot-die coating.</a> Nat. Commun. 3, 1002 (2012).</li><li>Liang, J., Li, L., Niu, X., Yu, Z., Pei, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elastomeric+polymer+light-emitting+devices+and+displays.">Elastomeric polymer light-emitting devices and displays.</a> Nat. Photonics. 7 (10), 817-824 (2013).</li><li>Yang, Y., Pei, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+blue-green+and+white+light-emitting+electrochemical+cells+based+on+poly+9,+9-bis+(3,+6-dioxaheptyl)-fluorene-2,+7-diyl.">Efficient blue-green and white light-emitting electrochemical cells based on poly 9, 9-bis (3, 6-dioxaheptyl)-fluorene-2, 7-diyl.</a> J. Appl. Phys. 81 (7), 3294-3298 (1997).</li><li>Tang, S., Buchholz, H. A., Edman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=White+Light+from+a+Light-Emitting+Electrochemical+Cell:+Controlling+the+Energy-Transfer+in+a+Conjugated+Polymer/Triplet-Emitter+Blend.">White Light from a Light-Emitting Electrochemical Cell: Controlling the Energy-Transfer in a Conjugated Polymer/Triplet-Emitter Blend.</a> ACS Appl. Mater. Iterfaces. 7 (46), 25955-25960 (2015).</li><li>Nishikitani, Y., Takizawa, D., Nishide, H., Uchida, S., Nishimura, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=White+Polymer+Light-Emitting+Electrochemical+Cells+Fabricated+Using+Energy+Donor+and+Acceptor+Fluorescent+&#960;-Conjugated+Polymers+Based+on+Concepts+of+Band-Structure+Engineering.">White Polymer Light-Emitting Electrochemical Cells Fabricated Using Energy Donor and Acceptor Fluorescent &#960;-Conjugated Polymers Based on Concepts of Band-Structure Engineering.</a> J. Phys. Chem. C. 119 (52), 28701-28710 (2015).</li><li>Sun, M., Zhong, C., Li, F., Cao, Y., Pei, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Fluorene&#8722;+Oxadiazole+Copolymer+for+White+Light-Emitting+Electrochemical+Cells.">A Fluorene&#8722; Oxadiazole Copolymer for White Light-Emitting Electrochemical Cells.</a> Macromolecules. 43 (4), 1714-1718 (2010).</li><li>Tang, S., Pan, J., Buchholz, H., Edman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=White+Light-Emitting+Electrochemical+Cell.">White Light-Emitting Electrochemical Cell.</a> ACS Appl. Mater. Interfaces. 3 (9), 3384-3388 (2011).</li><li>Tang, S., Pan, J., Buchholz, H. A., Edman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=White+light+from+a+single-emitter+light-emitting+electrochemical+cell.">White light from a single-emitter light-emitting electrochemical cell.</a> J. Am. Chem. Soc. 135 (9), 3647-3652 (2013).</li><li>Nishikitani, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=White+polymer+light-emitting+electrochemical+cells+using+emission+from+exciplexes+with+long+intermolecular+distances+formed+between+polyfluorene+and+&#960;-conjugated+amine+molecules.">White polymer light-emitting electrochemical cells using emission from exciplexes with long intermolecular distances formed between polyfluorene and &#960;-conjugated amine molecules.</a> J. Appl. Phys. 118 (22), 225501 (2015).</li><li>Tang, S., Mindemark, J., Araujo, C. M. G., Brandell, D., Edman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identifying+Key+Properties+of+Electrolytes+for+Light-Emitting+Electrochemical+Cells.">Identifying Key Properties of Electrolytes for Light-Emitting Electrochemical Cells.</a> Chem. Mater. 26 (17), 5083-5088 (2014).</li></ol>

The authors have nothing to disclose.

Le LEC possède une couche active contenant VFI hydrophobe et d&#39; amines aromatiques, et hydrophiles d&#39; oxyde de polyéthylène et le KCF 3 SO 3. Parce que ces matériaux ont des solubilités très différentes, une préparation minutieuse de la solution de revêtement par centrifugation est essentiel pour éviter la solvatation incomplète. Chacun doit être d&#39;abord dissous séparément et complètement dans les solvants avec la capacité de solvatation suffisante, les solutions sont m?...

Research and development of polymer light-emitting electrochemical cells (PLECs) have expanded in recent years.1-15 PLECs are similar to organic light-emitting diodes (OLEDs) in that both are surface emitting organic devices and are expected to find their way into future lighting applications. OLEDs are already on the market, but the cost is still high, one reason being that OLEDs need a complicated device structure with multiple layers. In contrast, PLECs have a very simple device structure which consists of a single active layer (emitting layer) between a pair of electrodes. This means that PLECs are suited to mass production processes such as roll-to-roll printing and coating. 
A PLEC has an active layer consisting of a fluorescent &#960;-conjugated polymer (FCP). The FCP can be electrochemically doped with a polymer electrolyte (a mixture of an ion conducting polymer and a salt). The FCP is p-doped on the anode side and n-doped on the cathode side during operation, and generates excitons which emit light between the p- and n-doped regions. Therefore, the emission color reflects the exciton emission (=fluorescence) wavelength of the FCP.
Stable white light emission is important for lighting applications, and color mixing techniques which employ two or more emitters have been widely used to achieve this.10-14 Recently, we presented a different approach for obtaining stable white light emission, using an active layer which contains blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and &#960;-conjugated aromatic amines15. This white light emission comes from exciplexes formed between PFD and amine molecules in excited states. Exciplex emission has a broader spectrum compared to the exciton emission from the PDF and/or amines, which gives it a color close to that of natural light. This translates to a higher color rendering index (CRI), which is preferable for lighting applications.
In this article, the authors describe the procedure used to fabricate the exciplex based LECs and show the stability of their white light emission.

<table><tbody><tr><td>Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD)</td><td>Aldrich</td><td>571660</td><td></td></tr><tr><td>4,4&amp;rsquo;,4&amp;rsquo;&amp;rsquo;-Tris[2-naphthyl(phenyl)amino] triphenylamine (2-TNATA)</td><td>Aldrich</td><td>768669</td><td></td></tr><tr><td>9,9-Dimethyl-&lt;em&gt;N,N&amp;rsquo;&lt;/em&gt;-di(1-naphthyl)-&lt;em&gt;N,N&amp;rsquo;&lt;/em&gt;-diphenyl-9H-fluorene-2,7-diamine (DMFL-NPB)</td><td>Aldrich</td><td></td><td></td></tr><tr><td>Poly(ethylene oxide) (PEO)</td><td>Aldrich</td><td>182028</td><td></td></tr><tr><td>Potassium tirifluoromethansulfonate (KCF&lt;sub&gt;3&lt;/sub&gt;SO&lt;sub&gt;3&lt;/sub&gt;)</td><td>Aldrich</td><td>422843</td><td>dried under vacuum at 200 &amp;deg;C for 2&amp;nbsp;hr prior to use</td></tr><tr><td>Chloroform</td><td>Kanto Chemical Co.</td><td>08097-25</td><td>dehydrated</td></tr><tr><td>Cyclohexanone</td><td>Kanto Chemical Co.</td><td>07555-00</td><td></td></tr><tr><td>SCAT 20-X (detergent)</td><td>Daiichi Kogyo Seiyaku</td><td></td><td>diluted with water</td></tr><tr><td>Acetone</td><td>Kanto Chemical Co.</td><td>01866-25</td><td>Electronic grage</td></tr><tr><td>2-propanol</td><td>Kanto Chemical Co.</td><td>32439-75</td><td>Electronic grage</td></tr><tr><td>13 mm GD/X Disposable Filter Device PVDF Filter Media, Polypropylene Housing</td><td>Whatman</td><td>6872-1304</td><td></td></tr><tr><td>UV/O&lt;sub&gt;3&lt;/sub&gt; Treating Unit</td><td>SEN Lights Co.</td><td>SSP16-110</td><td></td></tr><tr><td>Spectral Photo Detector</td><td>Otsuka Electronics</td><td>MCPD 9800</td><td></td></tr><tr><td>Voltage Current Source Monitor</td><td>ADCMT</td><td>6241A</td><td></td></tr><tr><td>Evaporation Mask</td><td>Tokyo Process Service Co., Ltd.</td><td>NA</td><td>The evaporation mask was wet-etched to create openings for patterned deposition of aluminum. The size of the mask is 100 mm x 100 mm x 0.2&amp;nbsp;mm-thick.</td></tr></tbody></table>

fabrication of white light-emitting electrochemical cells with stable emission from exciplexes

Les auteurs présentent une approche de fabrication stable blanc émission de lumière à partir de cellules électrochimiques polymère émettrices de lumière (Plecs) ayant une couche active qui consiste en poly bleu fluorescent (9,9-di-n-dodecylfluorenyl-2,7-diyl) ( PFD) et des molécules de triphénylamine π-conjugués. Cette émission de lumière blanche provient de exciplexes formés entre PFD et amines dans les états électroniques excités. Dispositif contenant VFI, 4,4 &#39;, 4&#39; &#39;- tris [2-naphtyle (phényl) amino] triphénylamine (2-TNATA), le poly (oxyde d&#39;éthylène) , et K 2 CF 3 SO 3 montre émission de lumière blanche avec la Commission internationale de l&#39;éclairage (CIE) coordonne de (0,33, 0,43) et un indice de rendu des couleurs (IRC) de Ra = 73 à une tension appliquée de 3,5 V. les mesures de tension constante a montré que la CIE coordonne de (0,27, 0,37), Ra de 67 ans, et la couleur d&#39;émission observée immédiatement après l&#39;application d&#39;une tension de 5 V étaient pratiquement inchangés et stables après300 s.

L&#39;électroluminescence (EL) spectres ont été utilisés pour calculer les coordonnées de la CIE et les valeurs CRI (figures 2, 4, 5). Les images photographiques des dispositifs électroluminescents ont été collectés pour vérifier la blancheur de l&#39;émission (figure 3). Les spectres EL des dispositifs de PFD amine dopé et le dispositif de VFI non dopé sont présentés dans la <s...

Watch this Scientific Journal Video about Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes at JoVE.com

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

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.

Fabrication de lumière blanche émettant des cellules électrochimiques avec des émissions de Stable exciplexes

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

fabrication-white-light-emitting-electrochemical-cells-with-stable

Research

JoVE Journal

Engineering

8.0K vues.  JX Nippon Oil & Energy Corporation. 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.

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

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date.

An integrated device, incorporating a dye-sensitized solar cell and triplet-triplet annihilation up-conversion unit was produced, affording enhanced light harvesting, from a wider section of the solar spectrum. Under modest irradiation levels a significantly enhanced response to low energy photons was demonstrated, yielding a record figure of merit for dye-sensitized solar cells.

L&#39;intégration d&#39;un système Annihilation Up-conversion triplet triplet visant à accroître à colorant cellule solaire réponse au sous-bande interdite Lumière

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents ...

Recherche

Ingénierie

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.

Synthèse chimique intensification des émetteurs de Fluorescence retardée thermiquement activées basé sur le Core dibenzothiophène-S, S-dioxyde

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 ...

Chimie

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.

Résolution temporelle des composés organiques Photophysiques caractérisation du Triplet-récolte à un sans oxygène environnement utilisant un iCCD caméra

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

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.

Production et caractérisation du vide a déposé des Diodes électroluminescentes organiques

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

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

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 displays and solid-state lighting technologies. The brightness and efficiency of blue QDs-based light-emitting diodes (LEDs) remain inferior to their red and green counterparts, due to the inherently unfavorable energy levels of different colors of light. To solve these problems, a device structure should be designed to balance the injection holes and electrons into the emissive QD layer. Herein, through a simple autoxidation strategy, pure blue QD-LEDs which are highly bright and efficient are demonstrated, with a structure of ITO/PEDOT:PSS/Poly-TPD/QDs/Al:Al2O3. The autoxidized Al:Al2O3 cathode can effectively balance the injected charges and enhance radiative recombination without introducing an additional electron transport layer (ETL). As a result, high color-saturated blue QD-LEDs are achieved with a maximum luminance over 13,000 cd m-2, and a maximum current efficiency of 1.15 cd A-1. The easily controlled autoxidation procedure paves the way for achieving high-performance blue QD-LEDs.

A protocol is presented for fabricating high-performance, pure blue ZnCdS/ZnS-based quantum dots light-emitting diodes by employing an autoxidized aluminum cathode.

Injection électronique améliorée et le Confinement d’Exciton de Quantum-point bleu Pure Light - Emitting Diodes en introduisant partiellement oxydés Cathode en aluminium

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 ...

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The cholesteric LC is composed of a nematic LC 4&#39;-pentyloxy-4-cyanobiphenyl (5OCB), redox-responsive chiral dopant (FcD), and a supporting electrolyte 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIm-OTf). The most important component is FcD. This molecule changes its helical twisting power (HTP) value in response to redox reactions. Therefore, in situ electrochemical redox reactions in the LC mixture allow for the device to change its reflection color in response to electrical stimuli. The LC mixture was introduced, by a capillary action, into a sandwich-type ITO glass cell comprising two glass slides with patterned indium tin oxide (ITO) electrodes, one of which was coated with poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol) doped with perchlorate (PEDOT+). Upon application of +1.5 V, the reflection color of the device changed from blue (467 nm) to green (485 nm) in 0.4 s. Subsequent application of 0 V made the device recover the original blue color in 2.7 s. This device is characterized by its fastest electrical response and lowest operating voltage among any previously reported cholesteric LC device. This device could pave the way for the development of next generation reflective displays with low energy consumption rates.

A protocol for the fabrication of a reflective cholesteric liquid crystalline display device containing a redox-responsive chiral dopant allowing quick and low-voltage operation is presented.

Un dispositif de cristallin Liquid cholestérique électrochimique pour la Modulation de la couleur rapide et à basse tension

We demonstrate a method for fabricating a prototype reflective display device that contains cholesteric liquid crystal (LC) as an active component. The ...

Preparing a Celadonite Electron Source and Estimating Its Brightness

The electron celadonite source described here performs well in a low-energy electron point-source projection microscope in long-range imaging. It presents major advantages compared to sharp metal tips. Its robustness affords a lifetime of months and it can be used under relatively high pressure. The celadonite crystal is deposited at the apex of a carbon fiber, maintained itself in a coaxial structure ensuring a spherical beam shape and easy mechanical positioning to align the source, the object and the electron-optical system axis. There is a single crystal deposition via generation of celadonite-containing water droplets with a micropipette. Scanning electron microscopy observation can be performed to verify the deposition. However, this adds steps and therefore increases the risk of damaging the source. Thus, after preparation, the source is usually inserted directly under vacuum in the projection microscope. A first high voltage supply provides the kick-off needed to start the electron emission. The field emission process involved is then measured: it has already been observed for dozens of electron sources prepared in this way. The brightness is under-estimated through an over-estimation of source size, intensity at one energy and cone angle measured in a projection system.

The article presents a protocol to prepare a celadonite source and estimate its brightness for use in a long-range imaging low-energy electron point-source projection microscope.

Préparation d'une source d'électron sédonite et estimation de sa luminosité

The electron celadonite source described here performs well in a low-energy electron point-source projection microscope in long-range imaging. It presents ...

Development of Efficient OLEDs from Solution Deposition

The use of highly efficient organic emitters based on the thermally activated delayed fluorescence (TADF) concept is interesting due to their 100% internal quantum efficiency. Presented here is a solution deposition method for the fabrication of efficient organic light-emitting diodes (OLEDs) based on a TADF emitter in a simple device structure. This fast, low-cost, and efficient process can be used for all OLED emissive layers that follow the host-guest concept. The fundamental steps are described along with necessary information for further reproduction. The goal to establish a general protocol that can be easily adapted for principal organic emitters currently under study and development.

Presented here is a protocol for the fabrication of efficient, simple, solution-deposited organic light-emitting diodes with low roll-off.

Développement d’OLED efficaces à partir du dépôt de solution

The use of highly efficient organic emitters based on the thermally activated delayed fluorescence (TADF) concept is interesting due to their 100% ...

Synthèse hydrothermale de nanoparticules luminescentes persistantes

Synthesis of Persistent Luminescent Nanoparticles for Rewritable Displays and Illumination Applications

Persistent luminescent nanoparticles (PLNPs) possess the capabilities to maintain extended longevity and robust emission even after the excitation has ceased. PLNPs have been widely used across various domains, including information displays, data encryption, biological imaging, and artistic decoration with sustained and vivid luminosity, providing boundless possibilities for a variety of innovative technology and artistic projects. This protocol focuses on an experimental procedure for the hydrothermal synthesis of PLNPs. The successful synthesis of enduring luminescent nanomaterials with Mn2+ or Cr3+ serving as a luminescent center in Zn2GeO4: Mn (ZGO: Mn) or ZnGa2O4: Cr highlights the universality of this synthetic method. On the other hand, the optical properties of ZGO: Mn can be changed by adjusting the pH of precursor solutions, demonstrating the tunability of the protocol. When charged with ultraviolet (UV) at a wavelength of 365 nm for 3 min and then stopped, PLNPs exhibit the remarkable capacity to generate afterglow efficiently and consistently, which makes them ideal for making two-dimensional rewritable displays and three-dimensional transparent, luminous artworks. This protocol outlined in this paper provides a feasible method for the synthesis of persistent luminescent nanoparticles for further illumination and imaging applications, opening up novel prospects for the fields of science and art.

Pleins feux sur l’auteur : Faire progresser la bio-imagerie et la thérapie avec des nanomatériaux fonctionnels

A protocol is presented for the synthesis of persistent luminescent nanomaterials (PLNPs) and their potential applications in rewritable displays and artistic processing utilizing the afterglow effect under ultraviolet light (365 nm) irradiation.

Synthèse de nanoparticules luminescentes persistantes pour des applications d’affichage et d’éclairage réinscriptibles

Persistent luminescent nanoparticles (PLNPs) possess the capabilities to maintain extended longevity and robust emission even after the excitation has ...

Fabrication de lumière blanche émettant des cellules électrochimiques avec des émissions de Stable exciplexes

Résumé

Explorer plus de vidéos

PLAYLIST