Quantum Confinement and Phase Transition in PbS nanowire
Abstract
Description
We report first principles density functional calculations of electronic structures and energy bandgaps ($ΔE_g$) in PbS nanowires (NW). The $ΔE_g$ is tuned by varying the diameter of the NW - {\it revealing the role of quantum confinement}.
The compressive radial strain (CS) on the NW is shown to be responsible for semiconducting to metallic phase transition. The conduction band (CB) of the NW, which has significant contribution from the excited 3{\it d}-orbital of S, is found to be more sensitive to the CS with the CB minimum shifting towards and eventually crossing the Fermi energy with increasing CS. The origin of the observed phase transition in a recent experiment is attributed to the CS on the PbS nanowire.
Submitted for review on 16th February 2009
Submitted for review on 16th February 2009