Infrared emitting PbSe nanocrystals for telecommunications window applications

We demonstrate the colloidal synthesis of PbSe nanocrystal quantum dots, via an organometallic-precursor route, developed from recently reported techniques. This synthesis typically yields a particle size distribution of approximately 5-10%, as may be inferred from the sharp spectral features seen in absorption and from our effective-mass model correlating spectral features to nanocrystal size. An accurate quantitative analysis, using an infrared reference dye, shows these nanocrystals to exhibit infrared photoluminescence from intrinsic quantum-confined states, with high quantum efficiencies of up to 60% in solution. The wavelength of the photoluminescence may also be conveniently size tuned in order to access the 1.3-1.5 μm 'telecommunications window'. We discuss the significance of this work in the context of future optoelectronic applications.