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).
Optical characterisation of poly-2,5-diheptyl-1,4-phenylene-alt-2,5-thienylene
Gadermaier, C.;
2000-01-01
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).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
