Microstructural and optical properties of spherical lead sulphide quantum dots-based optical sensors

Lead sulphide (PbS) quantum dots (QDs) are used as a Pb²⁺-ion-selective sensor and infrared detector. Also, the unique surface-sensitive properties make PbS QDs great potential in the development of optical sensors. In this research, the authors present a facile, effective and green route for the synthesis of well-defined spherical PbS QDs through the reaction between lead nitrate and sodium sulphide by virtue of its strong reduction and selective interaction abilities without using any surfactant, and evaluate its potential for use in optical and biosensing applications. The lattice parameter, crystallite size, average internal stress, microstrain and optical properties of the PbS QDs were calculated. The synthesised particles had well-defined spherical morphology, and the photoluminescence study showed that the emission spectrum was a strong and narrow band with high intensity that confirmed the high-quality luminescence properties of the prepared PbS QDs and its potential for optical sensing applications.