Stable colloidal quantum dot-based infrared photodiode: multiple passivation strategy

PbS colloidal quantum dots (QDs) are promising infrared detecting materials because of their widely tunable bandgap spanning the visible to the mid-infrared region, low exciton binding energy, and high electron and hole mobility. PbS QD photodiodes (PDs) exhibit high specific detectivity and high energy convergence efficiency. However, the performance of PbS QDPDs has been limited by the poor degree of ligand passivation on PbS QDs, resulting in oxidation and aggregation of the QDs. Herein, we review the surface morphology of PbS QDs and advanced methods for surface passivation of large PbS QDs. The various methods highlighted in this article provide scientific insight for promoting the commercialization of PbS QDPDs in the near future.