Acceptor layer

Figure 20. Fluorescence decay curves of J-aggregate ([CI-MC] [AA] = 1 2) in LB films combined with spacer and acceptor layers.

Figure 25. Plots of the log(lo/l -1) against the distance between the donor and the acceptor layers. Structure of the composite LB films with the donor - spacer - acceptor layers in the insert.

Figure 59 (Top) Steady-state emission spectra (Xexc = 450 nm) of adsorbed monolayers of Coum-PAH and Fl-PAH polycations, PdTAPP+, and the coadsorbed coumarin-flu-orescein-porphyrin triad. (Bottom) Emission spectra of a similar triad containing PdT-SPP4, with and without an added viologen electron acceptor layer. (From Ref. 43a. Copyright 1999 Elsevier Publications.)...

Solar cells devices based on CuPc and C6o fullerene have reached power conversion efficiencies of up to 5% [266,271], the highest efficiency for a Pc-containing solar cell being represented by a tandem cell in which two cells, each of them composed of a mixed donor/acceptor CuPc/C6o layer sandwiched between homogeneous donor and acceptor layers, are coupled (efficiency = 5.7%) [272],... 

Such bilayers were studied by photoluminescence, with a view to extracting the degree of photoluminescence quenching induced by a thin acceptor layer on the polymer [18]. Studies of photoluminescence quenching in bilayers have corroborated the picture derived from studies of photoelectrical performance. The short exciton diffusion length in PEOPT is 5 nm, consistent with both PL quenching and photodiode performance. 

A reasonable question to ask is the following. If one layer (the acceptor layer) in CaBe2Ge2 is more stable than the other, the donor layer, why does the CaBe2Ge2 structure form at all Why doesn t it go into a ThCr2Si2 structure based on the acceptor layer alone The answer lies in the balance of covalent and dative interactions for some elements the binding energy gained in donor-acceptor interlayer interactions overcomes the inherent stability of one layer isolated.39c... 

Figure 5.26 shows an LB film that regulates electron transfer. Monolayers of an electron donor layer, an insulating fatty acid layer and an electron acceptor layer were transferred in a defined sequence. In this hetero-layered LB film, electron transfer only occurs from the inside to the outside, and the structure of the insulator layer determines the efficiency of electron transfer. Swapping aroimd the donor layer and the acceptor layer reverses the direction of electron transfer. Simply controlling the layering structure therefore enables us to modulate the direction and efficiency of electron flow. 

Introduction of a mixed donor-acceptor layer in between the pure donor and acceptor layers, to increase the interfacial area for charge separation and thereby enable an increase in the optical depth without losses in light harvesting (Heutz et a/.,2004 Xueet a/., 2005). 

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