ELECTROLUMINESCENCE OF REGIOREGULAR POLY(ALKYLTHIOPHENES)

Citation
P. Barta et al., ELECTROLUMINESCENCE OF REGIOREGULAR POLY(ALKYLTHIOPHENES), Advanced materials for optics and electronics, 6(5-6), 1996, pp. 406-408
Citations number
11
Categorie Soggetti
Material Science",Optics,"Engineering, Eletrical & Electronic",Chemistry
ISSN journal
10579257
Volume
6
Issue
5-6
Year of publication
1996
Pages
406 - 408
Database
ISI
SICI code
1057-9257(1996)6:5-6<406:EORP>2.0.ZU;2-3
Abstract
Regioregular poly(4,4'-didecyl-2,2'-bithiophene) with exclusively head -to-head and tail-to-tail couplings between adjacent alkylated thiophe ne rings was studied as a potential material for the active layer in l ight-emitting diodes (LEDs). Readily visible green light was derived f rom a single layer LED structure, The electroluminescence (EL) spectru m peaks at 2.2 eV, Excitation of photoluminescence (PL) resulted in gr een light with the spectrum peaked at 2.3 eV. Additionally to the elec troluminescence and photoluminescence measurements, the absorption spe ctrum is reported, Determination of the optical energy gap gave E(g) e qual to 2.9 eV, The same experiments performed for another regioregula r polyalkylthiophene system (with only head-to-tail couplings) showed extremely poor EL and PL intensity, below the sensitivity of our spect rometer, The difference in yield of photo- and electroluminescence is likely interpreted in terms of trapping of excitons in conjugated bloc ks separated by head-to-head dyads, where they decay. Non-planarity of the polymer backbone also influences the relative positions of single t and triplet states.