Solution Electrochemiluminescent Cell with a High Luminance Using an Ion Conductive Assistant Dopant

Abstract

Conventional solution electrochemiluminescent (SECL) cells have a low luminance. In this paper, we propose an ion conductive assistant dopant (ICAD) system to improve the luminance of SECL cells. The SECL cell is assumed to have a simple structure of [transparent electrode/emitting solution/transparent electrode]. The solution of the cell consists of a mixed solvent (o-dichlorobenzene/acetonitrile=2/1 (vol/vol)), rubrene used as the emitting material, and 1,2-diphenoxyethane used as the ICAD. When voltage is applied to this SECL cell, the cell achieves a luminance of 183 cd/m2 and a luminous efficiency of 1.5 cd/A at 8 V with yellow emission. On the other hand, an SECL cell without an ICAD results in a low luminance of 0.3 cd/m2 at 8 V, corresponding to a conventional SECL cell. The ICAD improves the luminance 600 times by enhancing the ion conduction of rubrene cations in the solution. Furthermore, when the mixed solvent (o-dichlorobenzene/toluene=2/1 (vol/vol)), which has a high voltage resistance, is used in the SECL cell, the cell obtains a maximum luminance of 986 cd/m2 at 80 V. The features of the SECL cell are a simple cell structure and a transparent emitting area. SECL cells are expected to be used in unique displays with a see-through function for automobiles, windows, information equipment, and so on.

Electrochemiluminescent Systems as Devices and Sensors

“…Usually, the SECL cells have a structure of glass/indium-tin oxide (ITO)/emitting solutions/ITO/glass with dissolved organic (e.g., DPA or RUB) as well as inorganic compounds (e.g., Ru(bipy) 3 2 þ or Ir (ppy) 3 chelates) applied as active luminophores. 54,55,95,[176][177][178] During operation of SECL cell reduced and oxidized species are produced at each electrode (cathode and anode, respectively) by injected electrons and holes. The generated, usually ionic, intermediates move due to ion conduction in the solution with excitation of emitting species produced by annihilation of both redox forms.…”

Multi-color microfluidic electrochemiluminescence cells

“…Several fabrication methods for multi-color OLEDs have been proposed, including vacuum deposition of small molecular organic materials through a shadow mask [2] as well as solution processes such as screen [3,4] and ink-jet printing [5] for electroluminescent polymers. On the other hand, light-emitting devices based on liquid-emitting materials have been reported, such as liquid OLEDs [6,7] and electrochemiluminescence (or electrogenerated chemiluminescence) (ECL) cells [8][9][10][11][12][13][14][15]. Similar to OLEDs that employ solid-state emitters, liquid OLEDs and ECL cells can provide self-emission under appropriate applied voltages.…”

“…In contrast, the emitting layer of traditional ECL cells consists of well-established OLED materials dissolved in organic solvents such as acetonitrile [8], 1,2-dichlorobenzene [8,11], benzonitrile [9], and N, N-dimethylformamide [12]. Several studies on ECL have reported on the use of fluorescent dyes [8,12,14] and phosphorescent dyes [9].…”

“…Several studies on ECL have reported on the use of fluorescent dyes [8,12,14] and phosphorescent dyes [9]. ECL emission was produced by the collision of radical anions and cations generated at the cathode and anode surfaces, respectively.…”

Recent Advances in Research and Development of Microfluidic Organic Light-Emitting Devices

“…Recently, several researchers have focused on development of liquid-based liquid emitting devices using not only LOSs, but also electrochemiluminescence (ECL) solutions [32][33][34]. ECL is a light-emitting phenomenon generated by electrochemical reactions.…”