Summary from early, published work on devices using FRET or electron transfer

by manipulation of organized molecular systems Time-limited spectral sensitization using FRET and electron transfer by manipulation of organized molecular systems LB-layer d=0 nm electron transfer J-agg fluorescence at various distances d from AgBr surface FRET d=2.7 nm d=5.4 nm Möbius, Steiger 1975 CIBA GEIGY Patent 1976 « Manipulated» means: LB-layer transferred to a PVA foil which is then contacted with AgBr-crystal during limited time intervals

Fluorescent Paraquat Pesticide sensor CSEM Patent based on supramolecular organisation into J-aggregates and electron transfer Jagg fluorescence without Paraquat with some ppm Paraquat

Red emitting OLED for down-conversion by FRET using supramolecular organisation into J-aggregates ILFORD/EPFL No J-aggregate present J-aggregate + Alq3 Green fluorescence of Alq3 Energy transfer from UV excited green-emitting Alq3 to a red-emitting J-aggregate

Nanoporous Semiconductor NO2 sensor at room temperature based on electron transfer conductive, nanocristalline porous ITO coatings on flexible polymer substrates

n = 1.1-1.2 Nanocrystalline, mesoporous ITO coatings Nanoparticles ( 20-40 nm diameter, spheroids, SEM ) Resistance: 600 Ohms/ Transmission (VIS): 80% Thickness: 5600 nm (10 g ITO/m2) 5% PVA vs. ITO n = 1.1-1.2 A double layer shows 4x less resistivity, and 8%PVA vs. 5% 400 Ohm/ in a single layer and less cracking IR-reflectivity at 10 m:  45% ident. ITO BALZERS (vs. Al=100%) Pore Vol. BET: 0.29 ml/g Pore Diam. BET: 20 nm (spec.surf. 43 m2/g) Tested applications: - OLED with increased optical efficiency, see next slide - Gas sensor (NO2 ) - Ink-jet patterning – J-aggregates organized on this ITO smallest n, touch-screen conductivity like PEDOT, high IR refl., mech. and scotch-tape resistant. Ohm’s law fulfilled for electronic conduction.

2x enhanced Light extraction for Displays using low refractive index of nanoporous ITO and AlOOH coatings Waveguiding in glass