Direct Synthesis of CdSe Nanocrystals with Electroactive Ligands

Abstract

We report the synthesis and characterization of cadmium selenide nanocrystals with electro-active ligands directly attached to the surface. The conventional surfactant-assisted synthesis yields nanocrystals with surfaces functionalized with insulating organic ligands. These insulating ligands act as a barrier for charge transport between nanocrystals. Electro-active (reducing/oxidizing) ligands like ferrocene and cobaltocene have potential for applications as photo-excited hole conductors and photoredox systems. Although ferrocene ligands anchored to the nanocrystal surface through insulating long-chain hydrocarbon spacers have previously been reported, this approach is limited because the charge transfer between nanocrystal and ferrocene is highly sensitive to their separation. We report here ferrocene directly bound to the inorganic core of the nanocrystal and as a result the distance between the nanocrystals and the electroactive moiety is minimized. Graphic: CdSe nanocrystals are prepared directly with their surfaces passivated by electro-active ligands like ferrocene phosphine and phosphinoxide derivatives.

Colloidal Quantum Dots for Solar Technologies

“…In addition, typically the ligands are long-chain surfactant molecules, which serve 97 as electrical insulator in solar energy devices. 4,19,23,45,46 Thus, identifying new precursors for the low-temperature synthesis of QDs with short-chain ligands or electroactive ligands is an emerging direction.…”

“…43,96,98,99 Compared with organic dyes and polymers and inorganic QDs, carbon dots are thermal and photostable. 43,96,98,99 Other possible approaches to improving the efficiency of QD-based LSCs could use indirect-bandgap QDs (such as silicon QDs 97 ), tandem architecture, and plasmonic nanostructure to enhance absorption and emission.…”

“…summarizes the most recent achievements in QD-based LSCs. Among various types of QDs with direct bandgap, indirect bandgap silicon QDs have been used as emitters for high-efficiency LSCs 97. Silicon QDs are non-toxic, low cost, and ultra earth abundant, and they exhibit a large Stokes shift up to 400 meV, without any overlap between the absorption and emission spectra.…”

State‐of‐the‐Art and Trends in Synthesis, Properties, and Application of Quantum Dots‐Based Nanomaterials

“…Therefore, the ideal ligand should exhibit properties such as stable colloids, high conductivity, and stable and facile electronic interactions . Recently, the synthesis and characterization of CdSe QDs developed with ferrocene phosphine and phosphine oxide derivatives as electroactive ligands have been reported . This study reported that the inorganic cores of the nanoparticles were directly conjugated to ferrocene phosphine or phosphine oxide derivatives by their phosphine‐oxide functional group.…”

“…D) Energy dispersive X‐ray (EDX) analysis of CdSe sample capped with FcP(O)tBu2 composite, showing traces of elements including Cd, Se, Fe, and P (size: 7–7.5 nm). Reproduced with permission . Copyright 2016, American Chemical Society.…”