An Orange‐Emitting Phosphor (Ca, Mg)S:Mn, for Terminal Display Tubes

2 )] were performed in solution and in the solid states as Langmuir-Blodgett (LB) films. The type of the central metal of the complexes slightly altered the potentials of the electron transfer reactions. Redox peaks shifted toward the negative potentials as a function of the decreasing metal ion size. All complexes gave three reduction and one oxidation reactions with in the whole potential window of the electrolyte system. Due to the π-π interaction of phthalocyanine rings around the lanthanide metal ions the complexes were easily reduced at even positive potentials. Assignments of the redox processes, spectra and color of the electrogenerated species of the complexes were determined with in-situ spectroelectrochemical, and in-situ electrocolorimetric measurements. Various colors recorded during the electron transfer reactions well reflected electrochromic characters of the complexes. For practical usage, LB thin films of the complexes were easily coated on the ITO electrodes and investigated as electrochromic materials. All complexes displayed three distinctive color alternatives as green, orange, and red for their different redox states. Electrochromic measurements indicated that the nature of the metal ions in the phthalocyanine cavity alters the basic electrochromic parameters of the complexes. LB films of DyPc 2 and LuPc 2 were especially found as ideal neutral and anodic coloring electrochromic materials with their short response times, and high optical and coulombic stabilities.In addition to the wide range of the application fields, metallophthalocyanines (MPcs) have been extensively preferred in various electrochemical application technologies such as electrochromic, 1-3 semiconductor, 4,5 electrochemical sensor, 6-9 and electrocatalytic 10-12 applications because of their predominant electrochemical properties. 13,14 It is well known that basic electrochemical characterization of MPcs are directly related with the extensive π-electron delocalization of the Pc rings, redox activity of the central metals, and functionality of the substituent environments of the Pc ring. 15-17 Among phthalocyanine (Pc) derivatives, the syntheses of lanthanide (III) Pcs (LnPc 2 ) have attracted great attention due to the changing of the electrochemical responses of the complexes with the π-π interaction of the Pc rings of the sandwich complexes. 14,18-21 Altering the metal center and substituents of these type complexes easily affects their physical, electrical, optical, and electrochemical properties, 22-24 thus it is important to determine the electrochemical responses of the newly synthesized complexes to decide their possible application in different technologies. Therefore in this study, investigation of the electrochemical and spectroelectrochemical properties of a series of lanthanide (III) bis-phthalocyanines [samarium(III) (SmPc 2 ), europium (III) (EuPc 2 ), gadolinium (III) (GdPc 2 ), dysprosium(III) (DyPc 2 ) and lutetium(III) (LuPc 2 )] was aimed. The electrochromic features of the complexes were also examined...

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Electrochemical, Spectroelectrochemical, and Electrochromic Properties of Lanthanide Bis-Phthalocyanines

Orman

Koca

Özkaya

et al. 2014

“…CaS and SrS as members of the group II A -VI alkaline earth sulfides ͑AES͒ have been known for a long time as versatile and excellent phosphor host materials, and have regained great attention in recent years due to their potential for applications in displays. Doping with rare earth, transition ions, and even closed shell ions, a variety of photoluminescent ͑PL͒, 1,2 electroluminescent, [3][4][5] cathodoluminescent, 6,7 and photostimulable luminescent materials 8 can be developed. Investigation of Ca 1Ϫx Sr x S has indicated the bandgap dependence on x offers scope for tuning the PL emission spectrum with the addition of activator center.…”

mentioning

confidence: 99%

Preparation and Photoluminescence of CaS:Bi, CaS:Ag, CaS:Pb, and Sr[sub 1−x]Ca[sub x]S Nanocrystallites

Wang

Tang

Yang

et al. 2003

CaS:Bi, CaS:Ag, CaS:Pb, and Sr 1Ϫx Ca x S nanocrystallites were synthesized via a solvothermal method at a relatively low temperature. The method is more environmentally friendly than traditional preparations ͑very little sulfur-based gases are formed and the method does not involve toxic H 2 S or CS 2 ). Additionally, it is simple, convenient and produces a good yield. The products with an average diam of 30-100 nm were stable at humid air. The emission color of Sr 1Ϫx Ca x S nanocrystallites varied from blue ͑SrS͒ to red (Sr 0.6 Ca 0.4 S). The emitted light of CaS:Bi, CaS:Ag and CaS:Pb nanocrystallites are blue, red, and blue, respectively.

“…1,2 Potential applications in technology such as photodynamic therapy (PDT), 3,4 optical data storage, 5 non-linear optics, 6,7 chemical sensors, 8,9 liquid crystals, [10][11][12] semiconductors, 13,14 and electrochromic device [15][16][17][18][19] and electrocatalyts in fuel cell and electrolysis [20][21][22] have shown increased significance of these macrocycles.…”

mentioning

confidence: 99%

“…1,2 Although there are many paper on the electrochromism of phthalocyanines, detailed studies on the electrochromic properties of the phthalocyanines including coloration and write-erase efficiencies, switching times, and optical contrast are rare. 15,18,19,25,26 It is well documented in the literature that electrode modification techniques affected the electrochromic features of electrochromophores considerable and more satisfying responses were obtained with the films prepared with Langmuir Blodgett (LB) and electropolymerization methods. 15,27 Notwithstanding, the related studies for the electrochromism of electropolymerized phthalocyanines are still rare in the literature.…”

mentioning

confidence: 99%

Electrochromism of Electropolymerized Phthalocyanine-Tetrahydroquinoline Dyads

Arıcan¹,

Aktaş²,

Kanteki̇n³

et al. 2014

Electrochromic responses of metallophthalocyanines (MPcs) bearing redox active and electropolymerizable substituents were investigated. Excellent electrochromic responses were observed for metal-free and nickel phthalocyanines bearing electropolymerizable tetrahydroquinoline moieties (Phthalocyanine bearing 2,2,4,7-tetramethyl-3,4-dihydroquinoline, (THQ)) dyads; H 2 Pc-THQD and NiPc-DHQD). Although MPcs were not electropolymerizable complexes, they were easily electropolymerized on the working electrode after substituting with DHQ moieties. In order to investigate electrochromic features of the complexes, electrochemical and in-situ spectrochronocoulometric analyses of H 2 Pc-THQD and NiPc-THQD were first of all performed in solution and in solid states as their electropolymerized films to derive their possible usage as electrochromic materials. While both complexes gave common Pc ring based reduction reactions, they were coated on the working electrode with electropolymerization during oxidation reactions. Presence of THQ substituents caused electropolymerization of the complexes during the oxidation reactions. Then in order to examine their possible usages in the electrochromic application fields, phthalocyanine based composite electrodes were prepared with oxidative electropolymerization reactions. Finally their electrochromic features were investigated in different electrolyte systems. Electrochromic measurements showed that the electrodes modified with the electropolymerized films of H 2 Pc-THQD and NiPc-DHQD enhanced electrochromic properties to MPcs considerably. H 2 Pc-THQD and NiPc-THQD complexes illustrated excellent electrochromic parameters with high optical contrast, reasonable optical and columbic stabilities, and short response times.Phthalocyanines have been known as perfect functional materials for many decades, so multifarious technological applications have developed around these considerable interesting and enhanced materials. 1,2 Potential applications in technology such as photodynamic therapy (PDT), 3,4 optical data storage, 5 non-linear optics, 6,7 chemical sensors, 8,9 liquid crystals, 10-12 semiconductors, 13,14 and electrochromic device [15][16][17][18][19] and electrocatalyts in fuel cell and electrolysis 20-22 have shown increased significance of these macrocycles.Essential considerations for handling of phthalocyanines as electrochromic substances are particularly depend on their redox versatility, substitution alternatives with almost most metallic and some nonmetallic elements in the Pc central cavity, easy of modification by substituting the ring, easily coating on different surface (e.g. electrode) by various coating techniques and the most importantly electrochromic behaviors. 23,24 Although unsubstituted phthalocyanines are insoluble, substituting with different functional moieties increases their solubilities in common organic solvents and water. Especially long alkyl increases solubility of these complexes. 1,2 Although there are many paper on the electrochromism of phthalocy...