Abstract
Abstract Owing to their low cost, easy processing, and the possibility of flexible fabrication, polymer light-emitting diodes (PLEDs) are emerging as an important class of materials. Despite promising characteristics, the relatively easy ionization of the well-known low-work-function cathodes such as Ca and Ba prevents the full usage of these materials. Herein, we report the syntheses of three alcohol-soluble conjugated polymers with different conjugation lengths and electron affinities as electron injection and transport materials for PLEDs: poly[9,9-bis(2-dihexylaminoethoxy)fluorene-co-tetrafluorobenzene] (PFOH-1), poly[9,9-bis(2-dihexylaminoethoxy)fluorene-co-thiophene] (PFOH-2), and poly[9,9-bis(2-dihexylaminoethoxy)fluorene-co-benzo-thiadiazole] (PFOH-3). For comparison, devices using Al, Ca, and Al cathodes were also fabricated. The device based on the Al cathode showed lower performance with a luminescence efficiency of 0.93 cd/A and a luminance of 248 cd/m2; that based on the low-work-function metal Ca as the cathode showed a near-threefold increase in luminescence efficiency at 2.51 cd/A and brightness at 856 cd/m2 owing to greatly enhanced electron injection from the cathode; and the device employing the PFOH-3/Al cathode exhibited a luminescence efficiency of 2.35 cd/A and a brightness of 667 cd/m2 at a current density of 35 mA/cm2, which is comparable with the performance of the device with the Ca cathode.
Original language | English |
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Article number | 3130 |
Pages (from-to) | 206-211 |
Number of pages | 6 |
Journal | Organic Electronics: physics, materials, applications |
Volume | 25 |
DOIs | |
Publication status | Published - 2015 Jul 3 |
Externally published | Yes |
Keywords
- Alcohol-soluble
- Electron-transporting materials
- Fluorene-based copolymers
- PLEDs
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Chemistry(all)
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering