A facile and rapid synthesis of lead sulfide colloidal quantum dots using in situ generated H2S as the sulfur source

Abstract

We report on the synthesis of semiconductor PbS colloidal quantum dots with good size distribution through a facile and rapid approach using in situ generated H₂S as the sulfur source. This novel approach is easily reproducible and less energy consuming. It also has the advantages of low-input and high-output. The growth of PbS colloidal quantum dots should be controlled in 50–60 minutes to allow the rod-like CQDs with lengths of about 25–30 nm and widths of 3–5 nm to be obtained. The dodecylamine (DDA) is speculated to play a crucial role on the morphology of the products. Ligand exchange is performed to replace the oleic acid from the surface of PbS quantum dots by butylamine, aiming to strengthen the coupling between quantum dots and solve the transmission problem of the photo-generated carriers. At last, its electrical transport performance is evaluated as the conducting layer in an infrared photodetector.