Synthesis And Characterization Of Large Pbse Colloidal Quantum Dots

Large colloidal quantum dots of PbSe (first excitonic peak position >2 mu m) are synthesized under different conditions of temperature, the concentration of precursors and their ratio, and concentration of oleic acid and diphenylphosphine. The dependence of the optical properties, grain size dispersity, and process yield on the processing conditions is systematically explored and discussed. The Ostwald ripening process and how it affects grain growth is demonstrated. Finally, the results for the dependence of the absorption wavelength on the grain diameter for large nanocrystals are compared to the relationships reported in the literature for smaller nanocrystals.