Lattice contraction in free-standing CdSe nanocrystals

Colloidal CdSe nanocrystals (NCs) with high photoluminescent quantum yield are fabricated by a method adopting a large initial Se:Cd ratio of the precursors in the solution. X-ray diffraction and Raman measurements confirm that there exists lattice contraction in the free-standing wurtzite CdSe NCs. The lattice contraction indicates the occurrence of surface optimization/reconstruction during the growth, which results in the high quantum yield of the obtained CdSe NCs. (C) 2002 American Institute of Physics.