Solvent polarity-induced photoluminescence enhancement (SPIPE): A method enables several-fold increase in quantum yield of silicon nanoparticles

Incorporation of N and O into the Shell of Silicon Nanoparticles Offers Tunable Photoluminescence for Imaging Uses

“…50 In the same line, several reports attribute the blue-green PL in the nanosecond time domain of silicon nanostructures encompassing surface N/O− functionalities to radiative transitions of localized N/O trapping centers which share a similar charge-transfer character with the crystalline SiNPs. 5,11,42,52,53 The observed excitation wavelength-dependent PL is in line with that reported in the literature 54,55 for oxidized SiNPs derivatized with ligands capable of generating LUMO gaps. Herein, we have used mainly PA as a ligand, which is considered as being a ligand incapable of leading to the red shift PL phenomenon.…”

“…PL is greatly increased in the DMF solvent compared to water (see Figure 7), in line with literature reports, indicating that the PLQY of SiNPs colloids increases with decreasing solvent dielectric constant and is consistent with a CT state at the interface. 5,54 Final Discussion. SiNPs obtained from the wet chemical synthesis using commercial Mg 2 Si Zintl salts as precursors and ammonium chloride as oxidant were of an amorphous nature and contaminated with N and O functionalities.…”

Controlled tuning of radiative–nonradiative transition via solvent perturbation: Franck–Condon emission vs. aggregation caused quenching

“…[19][20][21][22] Interestingly, BIPM was found to follow a 'rise-and-fall' type fluorescence QY profile with solvent composition in the 1,4-dioxane (DiOx)-H 2 O system that could be utilized to fine tune its molecular emission. The variations were governed by the concerted interplay of polarity and proticity induced fluorescence enhancement 12,23,24 and aggregation caused quenching (ACQ) of fluorescence. [25][26][27] Such polarityproticity and aggregation guided bell-patterned fluorescence QY variation with whole emission in the UV region is rather unusual.…”

Are Fluorescent Silicon Nanoparticles Formed in a One-Pot Aqueous Synthesis?

“…In 2013, a new aqueous synthetic approach based on one-pot synthesis of fluorescent Si NPs, using of (3-aminopropyl)­trimethoxysilane (APTMS) as the silicon source and trisodium citrate dihydrate (Na 3 Cit), was reported by Zhong et al This work has attracted a great deal of attention from the scientific community since 2013 and has accumulated 227 citations according to Google Scholar (June 6, 2019), 203 citations according to Scopus (May 18, 2019), and 191 citations according to SciFinder (June 6, 2019). Among all these papers, special attention should be paid to those that specifically mention use of the approach described in this paper for the basis of or jumping off point for their own work. − At first inspection, the proposed technique seems to have many advantages in comparison with most other approaches reported earlier. Of these advantages, one can emphasize in particular the following: (i) water is used as a solvent, (ii) short reaction times are sufficient (15 min), (iii) low temperatures are needed (160 °C), and (iv) inexpensive precursors work well.…”