Intense and Stable Near-Infrared Emission from Light-Emitting Electrochemical Cells Comprising a Metal-Free Indacenodithieno[3,2-b]thiophene-Based Copolymer as the Single Emitter

• We report on the synthesis, characterization, and application of a series of metal-free near-infrared (NIR) emitting alternating donor/acceptor copolymers based on indacenodithieno[3,2-b]thiophene (IDTT) as the donor unit. A light-emitting electrochemical cell (LEC), comprising a blend of the copolymer poly[indacenodithieno[3,2-b]thiophene-2,8-diyl-alt-2,3-diphenyl-5,8-di(thiophen-2-y1)- quinoxaline-5,5'-diy1] and an ionic liquid as the single-layer active material sandwiched between two air-stable electrodes, delivered NIR emission (lambda(peak) = 705 nm) with a high radiance of 129 mu W/cm(2) when driven by a low voltage of 3.4 V. The NIR-LEC also featured good stress stability, as manifested in that the peak NIR output from a nonencapsulated device after 24 h of continuous operation only had dropped by 3% under N-2 atmosphere and by 27% under ambient air. This work accordingly introduces IDTT-based donor/acceptor copolymers as functional metal-free electroluminescent materials in NIR-emitting devices and also provides guidelines for how future NIR emitters should be designed for further improved performance.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

NATURVETENSKAP  -- Kemi -- Annan kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Other Chemistry Topics (hsv//eng)

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

charge-transport

highly efficient

electroluminescent polymers

conjugated polymers

field-effect transistors

diodes

enhanced photovoltaic performance

deep-red

organic electronics

heterojunction solar-cells

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