Shape control of PbS nanocrystals using multiple surfactants

Abstract

A novel technique is presented for preparing PbS nanorods with all spatial dimensionscomparable to the excitonic Bohr radius of PbS. The shape of the PbS nanocrystals isentirely controlled by using a combination of three different surfactants with different endfunctional groups. Oleylamine, oleic acid and trioctylphosphine are used to tune theshape of the PbS nanocrystals from cubic, stars, to rods and then to branchednanowires. The PbS nanorods have rock-salt structure with growth along the [220]direction.