ABSTRACT
Light emitting diodes of non-fully conjugated coil-like homopolymers and fully conjugated rigid-rod homopolymers with electron withdrawing or donating group were studied. A series of Poly[2,2-(m-2-X-phenylene)-4-4¡A-hexafluoroisopropane- bibenzoxazoles] (6F-PBO-X, with X = amine, hydrogen and nitro) and poly-p-(2-X- phenylene)-benzobisoxazole (PBO-X, with X = amine, hydrogen and nitro) were synthesized for light emitting diode applications to observe electroluminescence emission affected by electron withdrawing or donating group.
All polymers were fabricated identically to form bi-layer light emitting diodes. In the devices, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonite)(PEDOT:PSS) was applied to be a hole transport layer; indium tin oxide (ITO) was the anode; and aluminum was the cathode.
Devices of the non-fully conjugated coli-like polymers (6F-PBO-X) and the fully conjugated rigid-rod polymers (PBO-X) all showed threshold voltage about 4 V. In the electroluminescence (EL) spectrum, the maximum intensity of non-fully conjugated polymer (6F-PBO-X) with amine (-NH2), hydrogen (-H) or nitro (-NO2) functional group was at 499 nm, 505 nm and 515 nm, respectively, showing a 20 nm wavelength shift. From ¡VNH2, -H and ¡VNO2 groups, their Commission International de l`Eclairage (C. I. E.) coordinates were (0.30, 0.46), (0.34, 0.45) and (0.40, 0.46), respectively. The EL maximum intensity for fully conjugated rigid-rod polymer PBO-X was at 521 nm (-NH2) and 474 nm (-NO2) showing a 50 nm wavelength shift. Their C. I. E. coordinates were (0.42, 0.45) and (0.25, 0.38), respectively. This is attributed to the fully conjugated, collinear, coplanar, rigid-rod polymers (PBO-X) backbone readily affected by the push-pull functional groups showing a large red shift.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0712108-111917 |
| Date | 12 July 2008 |
| Creators | Wen, Hong-ta |
| Contributors | Kuo Shiao-Wei, Chen Ming, Bai S. J., Hong Jin-Long |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0712108-111917 |
| Rights | not_available, Copyright information available at source archive |
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