Electronic Excitation Energy Migration in a Photonic Dye–Zeolite Antenna

Abstract

Electronic excitation energy migration in a photonic antenna host-guest material has been investigated by time-resolved fluorescence experiments and by Monte Carlo calculations. The host consists of a linear channel system (zeolite L). The channels are filled with energy transporting dyes (donors) in their middle section and by one or several monolayers of a strongly luminescent trapping dye (acceptors) at each end of the channels. Excitation energy is transported among the donors in a series of steps until it reaches an acceptor at one end of the channels, or it is somehow trapped on its way, or it escapes by spontaneous emission. We describe the organization of dyes in the channels by means of Monte Carlo simulation and we report time-resolved data on a variety of pyronine-, oxonine-, and oxonine, pyronine-zeolite L materials. In the latter, the pyronine acts as donor and oxonine as acceptor. We find that the luminescence decay of crystals containing only one kind of dye is single exponential for moderate loading if measured under oxygen-free conditions, but biexponential otherwise. The main characteristic of the time evolution of oxonine, pyronine-zeolite L crystals is that the acceptor intensity is first built up before it starts to decay. This intensity increase becomes faster with increasing donor loading, a fact that beautifully supports the interpretation that the crystals behave as photonic antenna in which excitation energy is transported preferentially along the channels by a Förster-type mechanism until it reaches the acceptor, where it is emitted as red luminescence.

Designing Dye–Nanochannel Antenna Hybrid Materials for Light Harvesting, Transport and Trapping

“…[82,84,86,88,90] Electronic excitation energy transport along the channel axis, which means 1-dimensional transport, is increasingly favored with increasing loading, as can be deduced from Equation (2), [36] and has been observed experimentally. [10,[39][40][41] In Figure 9 C we observe a phenomenon known as luminescence concentration. Luminescent solar concentrators (LSCs) are a typical application where organized dye-ZL antenna can contribute to solve problems of efficiency and stability.…”

“…Cross-talking between molecules located in neighboring channels is, of course, possible and has been investigated theoretically and experimentally, to some extent. [36,[39][40][41][42] We do not investigate this further here, despite of the fact that it can be important. In order to realize noncentrosymmetric filling of the channels, one side of the channel opening must be blocked while keeping the other side open.…”

An integrative simulation model linking major biochemical reactions of actin-polymerization to structural properties of actin filaments

“…In the majority of numerical tests, the nSRF model considerably saved computational time and still gave outcome characteristics at the same confidence level as the complete SRF model. This result realistically enables the nSRF model to be applied for experimental data fitting and for deriving reaction rate constants on the same manner as reported in [48][49][50]. For situations were ATP-actin monomers are limiting the SRF model needs, however, to be used.…”

Injecting Electronic Excitation Energy into an Artificial Antenna System through an Ru2+ Complex

“…Time-resolved measurements of the Ox1 loaded crystals and of the coupled system were conducted as described in reference [17]. Layers of the samples were prepared on quartz plates.…”