Efficient blue-green and white light-emitting electrochemical cells based on poly[9,9-bis(3,6-dioxaheptyl)-fluorene-2,7-diyl]

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.364313· OSTI ID:527837

Yang, Y; Pei, Q ^[1]

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1. UNIAX Corporation, 6780 Cortona Drive, Santa Barbara, California 93117 (United States)

Efficient blue-green polymer light-emitting electrochemical cells, based on poly[9,9-bis(3,6-dioxaheptyl)-fluorene-2,7-diyl] (BDOH-PF), have been demonstrated. BDOH-PF has a high photoluminescent quantum efficiency of 73{percent} photon/photon in solid films. The polyether-type side groups of this polymer are built in to promote the ionic conductivity necessary for the operation of light-emitting electrochemical cells (LECs). Blue-green LECs using a blend of BDOH-PF and lithium triflate as the emissive layer, ITO and Al as the electrodes, achieve an external quantum efficiency of 4{percent} photons/electron and a luminous efficiency of 12 lm/W at 3.1 V. The brightness reaches {approximately}200 cd/m{sup 2} at 3.1 V, and exceeds 1000 cd/m{sup 2} at 3.5 V. When additional poly(ethylene oxide) (PEO) is blended into the emissive layer, phase separation between PEO and BDOH-PF occurs, and the emission becomes white. These white emitting LECs reach an external quantum efficiency of 2.4{percent} photons/electron and 400 cd/m{sup 2} brightness at a bias of 4 V. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 527837
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
BRIGHTNESS
ELECTROCHEMICAL CELLS
ELECTRODES
IONIC CONDUCTIVITY
LITHIUM COMPOUNDS
PHOTOLUMINESCENCE
POLYMERS
QUANTUM EFFICIENCY
VISIBLE RADIATION