And (yet) another abuse of ongarius blog for my personal research...
from P.N. Prasad, "Nanophotonics"
- block copolymer : color tunability with polymer length, PLED (Kyllo EM Synth. Met. 116, 189-192, 2001, Yang 1998), flexible aliphatic chain (spacer to enhance solubility), can comes in different morphologies like wrapped in sphere, multiphase, self-assembled to crystal etc. also white LED with multiple conjugated units
e.g. PPV (poly-p-phenylene vinylene), cf. Park C. Polymer 44, 6725 (2003)
electrically poled conjugated polymer by Langmuir-Blodgett Y-type deposition (hydrophobic interaction) and SAM (covalent) to enhance electro-optics effect, SHG
cf. Wijekoon J. Am. Chem. Soc. 118, 4480-4483 (1996), Zhu P. van der Boom, Chem Mater 14, 4983-4989 (2002): superlattice with much higher electro-optic coefficients and lower refractive index than LBO, automatically noncentrosymmetric, compatible with Si
- dendrimer: site isolation of core (Lanthanide ion, where vibrational quenching of solvent is suppressed), energy funnels for light harvesting (enhanced emission, amplification or lasing from the core center via energy transfer from peripheral groups), modulation of interaction
-supramolecular structures: mesoporous foldmer with central hollow tube (cavity or template for other photonic materials), discotic polymers with strong chirality and enhanced interdisc pi-pi interaction
- rare-earth ion: f-->another f or f-->d orbital, interionic coupling, coupling with phonon mode. e.g. Er3+ in glass fiber amplifier.
phonon interactions, multiphonon relaxation: depends on phonon density if state in host matrix (low frequency cut-off due to small size of nanostructure, another high-f cutoff), vibration amplitude, strength of el-ph coupling
cross-relaxation, ion-ion interaction induces transfer of excitation energy between ions
upconversion (photon avalanche): 1. excited state absorption leading to sequential absorption of same ions(why possible? not a third order process?) 2. energy transfer via ion-ion interaction 3. cooperative emission of two neighboring ions from a high-energy virtual state
down-conversion (quantum cutting)
