Controlling the dynamic behavior of light emitting electrochemical cells

• Published in: Organic electronics Vol. 14; no. 2; pp. 693 - 698
• Main Authors: Lenes, Martijn, Tordera, Daniel, Bolink, Henk J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2013; Elsevier
• Subjects: Applied sciences; Compound structure devices; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electroluminescence; Electroluminescent devices; Electronics; Exact sciences and technology; LECs; Light-emitting electrochemical cells; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optoelectronic devices; Other luminescence and radiative recombination; Physics; p–i–n Junction; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Space-charge limited current; p–i–n Junction; LECs; Space-charge limited current; Light-emitting electrochemical cells; Electroluminescent devices; Dynamic response; Speed; Driving voltage; Dynamic characteristic; Vibration; Chemical stability; Metal complex; Electrochemical cell; Electroluminescence; Transition metal; p i n junctions; Luminance voltage characteristics; p-i-n Junction; Space charge limited conduction; Driving device; Electroluminescent device; Interface; Charge carrier injection
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2012.12.005

[Display omitted] ► The device behavior of light-emitting electrochemical cells is studied. ► Fast current and luminance versus voltage sweeps during normal operation are analyzed. ► A universal set of curves can be identified in which different regimes are observable. ► The speed and extent in which the device evolves can be controlled. ► This enables the device to operate in its maximum efficacy state. Light emitting electrochemical cells (LECs) present an attractive route towards cost efficient lighting applications. By utilizing ionic phosphorescent transition metal complexes, efficient electroluminescence can be realized from a single layer device using air stable electrodes. These devices achieve efficient charge carrier injection due to ion accumulation at the interface upon driving, resulting in a dynamic response upon device operation. Here we investigate the device operation by using fast current and luminance versus voltage sweeps during normal fixed bias operating. A universal set of JL–V curves can be identified in which different regimes are observable. The speed and extent in which a LEC evolves through this set of curves can be controlled by varying the driving voltage, enabling the device to operate in it maximum efficacy state.