Light-emitting diodes copolymers

H.J. Brouwer, Semiconducting Polymers for Light-emitting Diodes and Losers a Structural. Photophysical and Electrical Study of PPV-type Alternating Copolymers and Oligomers, Ph.D. Thesis, Groningen, 1998. 

Y-H. Niu, J. Huang, and Y. Cao, High-efficiency polymer light-emitting diodes with stable saturated red emission use of carbazole-based copolymer blends in a poly(p-phenylene vinylene) derivative, Adv. Mater., 15 807-811, 2003. 

S. Jin, M. Kim, J.Y. Kim, K. Lee, and Y. Gal, High-efficiency polyfp-phenylene vinylene)-based copolymers containing an oxadiazole pendant group for light-emitting diodes, J. Am. Chem. Soc., 126 2474-2480, 2004. 

E.-N. Chang and S.-A. Chen, Cyano-containing phenylene vinylene-based copolymer as blue luminescent and electron transport material in polymer light-emitting diodes, J. Appl. Phys., 85 2057-2061, 1999. 

J. Lu, Y. Tao, M. D iorio, Y. Li, J. Ding, and M. Day, Pure deep blue light-emitting diodes from alternating fluorene/carbazole copolymers by using suitable hole-blocking materials, Macromolecules, 37 2442-2449, 2004. 

S.-H. Jin, M.-Y. Kim, D.-S. Koo, and Y.-I. Kim, Synthesis and properties of poly(fluorene-a/t-cyanophenylene vinylenej-based alternating copolymers for light-emitting diodes, Chem. Mater., 16 3299-3307, 2004. 

P. Herguth, X. Jiang, M.S. Liu, and A.K.-Y. Jen, Highly efficient fluorene and benzothiadiazole-based conjugated copolymers for polymer light-emitting diodes, Macromolecules, 35 6094-6100, 2002. 

V. Saxena and V.S. Shirodkar, A study of light-emitting diodes constructed with copolymers having cyclohexyl thiophene and hexyl thiophene units, J. Appl. Polym. Sci., 77 1051-1055, 2000. 

SJ. Bai, C.C. Wu, T.D. Dang, F.E. Arnold, and B. Sakaran, Tunable and white light-emitting diodes of monolayer fluorinatcd bcnzoxazole graft copolymer, Appl. Phys. Lett., 84 1656-1658, 2004. 

Due to the large band gap and high triplet energy level of the poly(3, 6-dibenzosilole) 5, the copolymer is an excellent host for the fabrication of blue polymer phosphorescent light-emitting diodes. A high external quantum efficiency (t/el) of 4.8% and a luminance efficiency of 7.2 cd/A at 644 cd/m2 have been achieved for blue phosphorescence devices (emission peak (AEL) at 462 nm, CIE coordinates x = 0.15,y = 0.26). The performances of the devices are much better than those reported for blue phosphorescent devices with poly(A--viny 1 cabarzo 1 e) (PVK) as the host.32... 

Fluorene- or fullerene-thiophene blends have been developed for enhanced photogeneration <2007CPC1497>, and use in light emitting diodes <2007MM6164>, and copolymers of oxadiazoles and thiophenes <2007MI236> have been used for non-linear optical applications. 

Electroactive fluorene copolymers, (I), were prepared by Uckert [1] using 2,7-diiodo-9,9-di-2-ethylhexyl fluorine. This product was used as a component in light-emitting diodes. 

TABLE 2. Light-emitting testing for fluorene copolymers in a light-emitting diode using different hole injection/transport layers. 

Subsequently, Cao et al. [30,31] designed and synthesized polymer 20-22 by similar method and the highly efficient saturated red-phosphorescent polymer light-emitting diodes (PLEDs) were achieved on the basis of copolymer 20. The best device performances are observed with an external quantum efficiency of 6.5% photon/electron (ph/el) at the current density of 38 mA/cm2, with the emission peak at 630 nm (x = 0.65, y = 0.31) and the luminance of 926 cd/m2. 

Paik K.L., Baek N.S., Kim H.K, Lee J.H., Lee Y., Macromolecules 35 (2002) 6782. White Light-Emitting Diodes from Novel Silicon-Based Copolymers Containing Both Electron-Transport Oxadiazole and Hole-Transt>ort Carbazole Moieties in the Main Chain pp 6782-6791 Publication Date (Web) August 2, 2002 (Article) EKDI 10.1021/ma020406r... 

Heischkel, Y. and Schmidt, H.-W. 1998. Synthesis of ABC-triblock copolymers for light emitting diodes. Macromol. Chem. Phys. 199 869-880. 

---