Pulsed laser irradiation synthesis of lead selenide quantum dots from lead and selenium salts in various surfactants

Abstract

Hypothesis: Semiconductor nanocrystals with response in the near-infrared region include lead chalcogenide quantum dots (QDs), and these materials show a strong quantum confinement effect due to their large Bohr radius compared with the group II-VI QDs. In the present study, a facile synthesis of lead selenide (PbSe) QDs using a pulsed laser irradiation in liquid (PLIL) is presented. Experiments: PbSe QDs were produced using a pulsed Nd:YAG laser (532 nm, 10 Hz, 7 ns) irradiation of the Pb and Se mixed precursor solutions using the following three surfactants at various concentrations: cetyl-trimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polyvinylpyrrolidone (PVP). Findings: Interestingly, it was observed that the synthesis and particle size of PbSe QDs obtained via the PLIL technique were strongly influenced by the type and concentration of the surfactants and by the varying wavelength and power of the laser. A secondary irradiation of the prepared sample in PVP solution resulted in the formation of rock salt crystalline PbSe QDs that were approximately 6.83 nm in size.