Optical Properties of Colloidal PbSe Nanocrystals

We present the structural and optical characterization of colloidal PbSe nanocrystals. The lowest-energy exciton transitions in these structures, with diameters between 3 and 8 nm, occur at wavelengths between 1.0 and 1.85 μm. Band-edge luminescence spectra with quantum yields as high as 80% are observed. Unexpectedly long (∼300 ns) luminescence lifetimes are observed. These properties are promising for applications in optoelectronics and microscopy.