Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†

Abstract

This article reports a comparative study of the energy transfer processes in solution and the solid state from poly(vinyl carbazole; the donor) to dimethylphenyl-terminated poly[(9,9-dioctylfluorenyl-2,7-divinylene-fluorene)-co-alt-{2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene}] (the acceptor). The results in solutions suggest that a decrease of the donor emission intensity with an increasing acceptor concentration is more closely related to the trivial energy transfer process, indicating that the donor and acceptor chains are not in close contact during the lifetime of the donor excited state. This conclusion was reached using the amplitude-averaged lifetime of the donor, which is practically independent of the acceptor concentration. In the solid state, the polymer blends showed a decrease in the donor emission with an increasing acceptor concentration, and a decrease in the donor lifetime was also observed. Thus, in the solid state, changes in morphology interfere with the nonradiative resonant energy transfer process, but influence on the trivial process cannot be completely neglected. The lifetime does not follow a continuous decrease with the PFO-MEHPV concentration like the emission intensity does. The changes in the lifetime values occur over the same concentration range as do the changes of morphology, as shown by the scanning electron micrographs.

Origin of White Electroluminescence in Graphene Quantum Dots Embedded Host/Guest Polymer Light Emitting Diodes

“…In more detail, τ 1 decreased from 4.63 to 4.23 ns, and τ 2 decreased from 19.71 to 16.73 ns. The decrease ratio of τ 2 is larger than that of τ 1 , which suggests that the carbazole excimer more contributed to the energy transfer process than that of isolated carbazole moiety34.…”

Structural Correlations between Luminescent Properties and Excited State Internal Proton Transfer in Some Zinc(II) N,N′-Bis(salicylidenes)

“…The excitation wavelengths correspond to the maximum of the absorption spectra Emission decays were analyzed using exponential functions, as previously described. [59][60][61] Time resolved emission spectra (TRES) were recorded using the same instrument. These spectra gave information on the spectra evolution with the time and provided additional evidences for the ESIPT process.…”

“…At least 10.000 counts in the peak channel were accumulated for lifetime measurements. Emission decays were analyzed using exponential functions, as previously described. − …”

Dual Emissions of Salicylidene-5-chloroaminepyridine Due to Excited State Intramolecular Proton Transfer: Dynamic Photophysical and Theoretical Studies

“…At least 10 000 counts in the peak channel were accumulated for lifetime measurements. The emission decays were analyzed using exponential functions. ,, …”

“…The emission decays were analyzed using exponential functions. 44,65,66 The time-resolved emission spectra (TRES) were recorded using the same instrument. TRES of the sal-5Cl-py in DMSO (λ exc = 335 nm and λ em = 365−625 nm; λ exc = 375 nm and λ em = 400−700 nm), MeOH (λ exc = 335 nm; λ em = 355−620 nm), DMSO + CF 3 COOH (λ exc = 335 nm; λ em = 350−550 nm), and MeOH + CF 3 COOH (λ exc = 335 nm; λ em = 350−550 nm) were recorded.…”