Light single-layer polymer

A characteristic dependence of the efficiency on the thickness of the active layer has also been observed for single layer polymer LEDs. This effect has been attributed to reflection of the EL light at the mirror-like metal electrodes resulting in characteristic interference maxima and minima depending on the thickness of the active layer and its refractive index [116). 

S Kan, X Liu, F Shen, J Zhang, Y Ma, Y Wang, and J Shen, Improved efficiency of single-layer polymer light-emitting devices with poly(vinylcarbazole) doubly doped with phosphorescent and fluorescent dyes as the emitting layer, Adv. Funct. Mater., 13 603-608, 2003. 

H. E Wittmcum, J. Grriner, R. H. Friend, G. W. C. Spencer, S. C. Moratti, A. B. Holmes, Microcavity Effect in a Single-Layer Polymer Light-Emitting Diode. Adv. Mater. 1995,7,541-544. 

The electroluminescent performance of single-layer polymer light-emitting diodes with their emissive layer of PVK and electron transporting molecules of iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,C ]-picolinate has been investigated [84]. 

Anthracene Groups. A homopolymer from 9-(4-vinylphenyl)anthracene emits green light originating from the excimer of the anthracene units. Ruores-cent vinyl polymers containing 9-phenylanthracene pendants were synthesized and examined as an emitter layer in organic electroluminescent devices. The single-layer polymer EL device uses the homopolymer. 

Suppression of the aggregate emission is possible in two quite different ways. At first, the aggregate emission could be almost completely shut out by simply diluting the LPPP 12 with a matrix polymer. LEDs with 1% LPPP 12 in poly(9-vinylcarbazole) PVK as emitter material are characterized by a pure blue light emission with a quantum efficiency of ca. 0.15% in single-layer configuration (lTO/1% LPPP 12 in PVK/Ca) 135],... 

Z. Bao, Z. Peng, M.E. Galvin, and E.A. Chandross, Novel oxadiazole side chain conjugated polymers as single-layer light-emitting diodes with improved quantum efficiencies, Chem. Mater., 10 1201-1204, 1998. 

Polymers based on 1,10-phenanthroline and chlorotricarbonylrhenium(I) were fabricated into single-layer light emitting devices. The turn-on voltage was 7 V with a 125 cd/m2 output. The electroluminescence maximum was broad and occurred at 700 nm [111]. 

---