Structural and electrical transport properties of PbS quantum dots under high pressure

The high-pressure investigation of the PbS nanocrystal quantum dots (NQDs) with large Bohr radius has been conducted by in situ high-pressure X-ray diffraction, high-resolution transmission electron microscopy and alternating current impedance spectroscopy experiments up to 41.0 GPa. PbS NQDs present a similar pressure-induced structure phase transition path to bulk and nanocrystal PbS. The electronic conduction and the ionic conduction coexist in PbS NQDs, and the resistivity is generally larger than bulk and nanocrystal PbS. Above 9.1 GPa, the deviatoric stress drives the fusion of the nanoparticles, which leads to the reduction or the disappearance of grain boundary effect as well as a great influence on the dielectric performance. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study found that PbS nanocrystal quantum dots exhibit a similar structural phase transition path to bulk and nanocrystal PbS under high pressure, with coexistence of electronic conduction and ionic conduction and generally higher resistivity. At pressures above 9.1 GPa, deviatoric stress drives the fusion of nanoparticles, leading to a reduction in grain boundary effect and a significant influence on dielectric performance.