PbSe/PbS quantum dots are tiny semiconductor particles with the size of three dimensions below 100 nanometers, belonging to the lead group of sulfur quantum dots. PbSe/PbS quantum dots are direct bandgap semiconductor materials with high absorption coefficient and narrow bandgap. The absorption and emission wavelengths of PbSe/PbS quantum dots can range from 800 nm to 3000 nm, which can cover the whole near-infrared band. Based on quantum size effect, the optical and electronic properties of PbSe/PbS quantum dots are completely different from their corresponding bulk materials. In addition, PbSe/PbS quantum dots have many other properties, including quantum confinement effect, surface effect, quantum tunneling effect, small size effect, Coulomb blocking effect, multiple exciton generation, and the others. With the advantages of multiple excitons generation, high light absorption and other good excitonic properties, PbSe/PbS quantum dots have become popular research subjects for many scientific researchers.
With the excellent optoelectronic performances, PbSe/PbS quantum dots are widely used in optical components.
Figure 1. An example of PbSe/PbS quantum dots applied in solar cell.
According to particle size distribution, PbSe/PbS quantum dots can be divided into narrow-distributed PbSe/PbS quantum dots and wide-distributed PbSe/PbS quantum dots.
The preparation methods of PbSe/PbS quantum dots include "Heat injection method" and "Cation exchange method".
Figure 2. An example of cation exchange method
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