CD Bioparticles has developed some new products, lead selenide core quantum dots (PbSe). These products have a specific property of size dependent optical/electronic performance. This series of PbSe size is ranges from 2.9 to 3.8 nm, whereas the emission spectrum (1200-1800 nm) has covered the near-infarred regions but is relatively narrow, which make it called as narrow gap semiconductors QDs. Traditional PbSe dots surface are coated by oleic aicd, which can passivate the holes and traps on the surface of the QDs while preventing the QDs from coagulating in an organic solvent.