Naphthalimide polymers for organic light-emitting diodes
Cacialli, F; Bouche, CM; Le Barny, P; Friend, RH; Facoetti, H; Soyer, F; Robin, P
| HERO ID | 3575474 |
|---|---|
| In Press | No |
| Year | 1998 |
| Title | Naphthalimide polymers for organic light-emitting diodes |
| Authors | Cacialli, F; Bouche, CM; Le Barny, P; Friend, RH; Facoetti, H; Soyer, F; Robin, P |
| Journal | Optical Materials |
| Volume | 9 |
| Issue | 1-4 |
| Page Numbers | 163-167 |
| Abstract | We used a side-chain polymer based on a high-electron affinity TEA) naphhalimide moiety (PNI), to fabricate single and double-layer light-emitting diodes (LEDs) with improved efficiency in the green spectral region. The chromophore is attached to a polymethacrylate backbone through a spacer and is characterised by a 30% photoluminescence quantum yield. In single-layer light-emitting diodes we find that the electroluminescence efficiency is not limited by Al cathodes a!, for poly(p-phenylene vinylene), PPV, as expected from consideration of the EA. We also report maximum internal quantum efficiencies of about 1.7% for Ca and 0.9% for Al in double-layer devices where PPV serves as both hole-injector and emitter. Tuning of emission in the red is possible by dye-doping (at high concentration) the PNI and causing the emission to happen in this layer. Unexpectedly, not only does the dye-doping of PNI red-shifts the emission spectrum, but also affects significantly the charge transport properties and in particular reduces the driving field necessary for electroluminescence in both single-and double-layer LEDs and we propose this effect as one of the factors for the lifetime increase upon doping recently reported in the literature [J. Shi, C.W. Tang, Appl. Phys. Lett. 70 (1997) 1665.]. (C) 1998 Elsevier Science B.V. |
| Wosid | WOS:000072743500030 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |