1. A Library of Selenourea Precursors to PbSe Nanocrystals with Size Distributions near the Homogeneous Limit
- Author
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Michael P. Campos, Jonathan S. Owen, Willem Walravens, Robert Andrew Swain, Matthew Y. Sfeir, Zeger Hens, Alexander N. Beecher, Gregory T. Cleveland, and Mark P. Hendricks
- Subjects
Surface Properties ,Exciton ,Selenourea ,Nucleation ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Biochemistry ,Catalysis ,Spectral line ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Organoselenium Compounds ,Urea ,Particle Size ,Selenium Compounds ,Molecular Structure ,General Chemistry ,Molar absorptivity ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Nanocrystal ,Lead ,Spectral hole burning ,Nanoparticles ,0210 nano-technology ,Doppler broadening - Abstract
We report a tunable library of N,N,N′-trisubstituted selenourea precursors and their reaction with lead oleate at 60–150 °C to form carboxylate-terminated PbSe nanocrystals in quantitative yields. Single exponential conversion kinetics can be tailored over 4 orders of magnitude by adjusting the selenourea structure. The wide range of conversion reactivity allows the extent of nucleation ([nanocrystal] = 4.6–56.7 μM) and the size following complete precursor conversion (d = 1.7–6.6 nm) to be controlled. Narrow size distributions (σ = 0.5–2%) are obtained whose spectral line widths are dominated (73–83%) by the intrinsic single particle spectral broadening, as observed using spectral hole burning measurements. The intrinsic broadening decreases with increasing size (fwhm = 320–65 meV, d = 1.6–4.4 nm) that derives from exciton fine structure and exciton–phonon coupling rather than broadening caused by the size distribution.
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