Synthesis of lead chalcogenide nanocrystals and study of charge transfer in blends of PbSe nanocrystals and poly(3-hexylthiophene)

Abstract

Nearly monodisperse lead chalcogenide (PbE, E = S, Se, or Te) semiconductor quantum dots of controllable shape have been produced via a novel synthesis which includes the occurrence of in situ formed Pb(0) particles. Tunable size and shape are achieved through appropriate choice of the precursor type and the stabilizer. As precursor, we use, on the one hand, lead oxide or lead acetate, on the other hand, tellurium, selenium, or sulfur powder dissolved in trioctylphosphine (TOP), tributylphosphine (TBP), or 1-octadecene (ODE). Oleic acid (OA) and various amines, as well as TOP and TBP are used for stabilization. With respect to possible application in hybrid solar cells, the surface of as-synthesized spherical PbSe nanocrystals was investigated by nuclear magnetic resonance (NMR), mass spectrometry (MS) and thermogravimetric analysis (TGA). As an important result, it was found that the surface is not mostly covered by oleic acid after synthesis, but by a phosphorus compound. We also applied a ligand exchange procedure with hexylamine and found evidence for the successful attachment of hexylamine to the nanocrystal surface. Additionally, charge separation between these nanoparticles and the conjugated polymer poly(3-hexylthiophene) (P3HT) is studied by electron spin resonance and photoinduced absorption spectroscopy. The spectra obtained suggest that charges can be produced successfully by photoinduced charge transfer.

One-pot synthesis of GSH-Capped CdTe quantum dots with excellent biocompatibility for direct cell imaging

“…Witt et al. synthesized PbSe QDs and studied the photoinduced charge transfer between QDs and poly(3-hexylthiophene) [22] . These QDs are primarily prepared via a hot injection organometallic route.…”

Curcumin-loaded nanoparticles enhance apoptotic cell death of U2OS human osteosarcoma cells through the Akt-Bad signaling pathway

“…The following abbreviations are used: s, singlet; d, doublet; m, multiplet. Mass spectra were measured with a Finnigan/Thermo Quest MAT 95XL instrument (52,53).…”

Synthesis and Characterization of Large PbSe Colloidal Quantum Dots

“…[ 12–16 ] The growth of PbSe quantum dots, primarily of smaller size grains, has already been reported in a number of publications. [ 6, 17–21 ] In this work we studied a comprehensive range of growth conditions and resulting optical properties of large (absorption beyond 2 µm) CQD of PbSe.…”

“…The tinting of the solution has been attributed to the formation of Pb particles. [ 18 ] This usually results in the formation of smaller grains and the process outcome becomes less predictable, apparently due to the presence of nuclei in the reaction mixture during injection of the Se precursor. Excessive nucleation was also observed to result from a small amount of accidental oxidation due to air bubbles, as well as from the use of Se precursors made from finely ground or aged materials.…”