As its emission in near-infrared region,lead chalcogenides(PbSe and PbS)have gained considerable attention in the last decade due to their potential applications in both fundamental research and technical application.Being with small bulk band-gap,high dielectric constant and large exciton Bohr radius,PbSe colloidal quantum dots(CQDs)have become an ideal material in various IR optoelectronic devices.Also,their properties can be tuned by the quantum size effect,allowing the effective bandgap tunable for a certain application.