Antenna Doping: The Key for Achieving Efficient Optical Wavelength Conversion in Crystalline Chromophoric Heterolayers

High-yield wavelength conversion is one of the key requirements for efficient photon energy harvesting. Attempts to realize by simply stacking layers chromophores have failed so far, even when using highly crystalline assemblies and employing recently discovered long-range (>100 nm) Förster resonance transfer (LR-FRET). Optical efficiency drastically improved chromophoric metal–organic framework heterolayers fabricated layer-by-layer in connection with an “antenna doping” strategy. Systematic investigations reveal that LR-FRET mechanism, reported previously aggregates, anisotropic neat materials but can be made more isotropic doping strategies. Using optimized fabrication parameters dopant concentrations, a three-layer, two-step cascade overall optical ≈75% realized.