| Popis: |
Liquid crystalline conjugated polymers have potential applications as inexpensive, easy to process polarized back lights for liquid crystal displays. Two 'Hairy rod' type conjugated polymers namely, Poly(9,9-dioctylfluorene) and Poly(9,9-dioctylfluorene-co-dithiophene), have been investigated as polarized light emitting materials. In this paper, we present polarized absorption and photoluminescence for films aligned on rubbed precursor PPV alignment layers. We also report electroluminescence measurements for oriented multi-layer devices with rubbed PPV hole transporting alignment layers that produced polarization ratios of up to 25:1 and a luminance of 250 cd/m 2 . Sample preparation, device fabrication and characterization are described. Preliminary investigations have been made into the performance of PPV as an alignment layer with respect to thermal degradation. |
