Title of article :
Optical characterisation of poly-2,5-diheptyl-1,4-phenylene-alt-2,5-thienylene
Author/Authors :
Loi، نويسنده , , M.A and List، نويسنده , , E.J.W and Gadermaier، نويسنده , , C and Graupner، نويسنده , , W and Leising، نويسنده , , G and Bongiovanni، نويسنده , , G and Mura، نويسنده , , A and Pireaux، نويسنده , , J.-J and Kaeriyama، نويسنده , , K، نويسنده ,
Abstract :
We have investigated the electronic properties and the photoluminescence (PL) decay of the poly-2,5-diheptyl-1,4-phenylene-alt-2,5-thienylene (PDHPT) copolymer made up by the regular alternation of high and low band-gap units. Experimental data show that the large twisting of the neighbouring constituents of the polymer chain leads to a considerable shift of the optical transitions towards high energies. This blue shift is much more pronounced than the expected band-gap lowering caused by the low-gap thiophene units. Transient PL experiments show that inter-chain migration of excitons towards centers where excitons decay non-radiatively reduces the PL quantum yield (QY).
Keywords :
5-diheptyl-1 , 5-thienylene , Low-gap thiophene units , Photoluminescence , excitons , Poly-2 , 4-phenylene-alt-2
