Lanthanide photoluminescence lifetimes reflect vibrational signature of local environment: Lengthening duration of emission in inorganic nanoparticles

Remarkable difference in pre-cation exchange reactions of inorganic nanoparticles in cases with eventual complete exchange

“…Recently, we have demonstrated a correlation of these lifetime components with the immediate environmental vibrational frequencies. 31 The trends in lifetime fitting parameters from the Zn(Tb)S/M [M = Hg/Pb] NPs are shown in Fig. 8.…”

“…In addition to this, these NPs provide spatial protection to Ln 3+ emission. [29][30][31] Experimental observations and rationalizing the charge trapping-mediated emission sensitization identifies Zn(Tb)S NPs as one of the suitable materials, in which ZnS NPs can sensitize and spatially protect Tb 3+ emission. 29,[32][33][34][35][36] A method to predict the favorable combination of the incoming-outgoing cation pair in a cation exchange reaction in inorganic NPs based on thermodynamic grounds is discussed by Alivisatos and coworkers.…”

“…In addition to this, these NPs provide spatial protection to Ln 3+ emission. 29–31 Experimental observations and rationalizing the charge trapping-mediated emission sensitization identifies Zn(Tb)S NPs as one of the suitable materials, in which ZnS NPs can sensitize and spatially protect Tb 3+ emission. 29,32–36…”

Evaluating Inter-Lanthanide Interactions in Co-Doped Zinc Sulfide Nanoparticles for Multiplex Assays

“…Important challenges to using Ln 3+ emissions in applications include extremely inefficient direct excitation and environmentally induced (from vibrational overtones) emission quenching. , A way to overcome these challenges is to design a Ln 3+ coordination environment with suitable moieties around them that can absorb electromagnetic radiation and feed the Ln 3+ energy levels efficiently, referred to as an optical antenna effect. − Various researchers are devoting attention to develop Ln 3+ molecular complexes toward this aim. Others are using semiconductor NPs as the sensitizer because of their appreciably higher molar extinction coefficient , and the low frequency of the phonon spectrum in the interior of the NPs which slows the nonradiative Ln 3+ excited-state relaxation . Beyond these important attributes, inorganic NPs can accommodate multiple distinct Ln 3+ luminophores that enable formation of multiplex assays.…”

“…Others are using semiconductor NPs as the sensitizer because of their appreciably higher molar extinction coefficient 12,13 and the low frequency of the phonon spectrum in the interior of the NPs which slows the nonradiative Ln 3+ excited-state relaxation. 14 Beyond these important attributes, inorganic NPs can accommodate multiple distinct Ln 3+ luminophores that enable formation of multiplex assays. Multiplex assays yield emissions at different wavelengths from a single excitation source.…”