A Library of Selenourea Precursors to PbSe Nanocrystals with Size Distributions near the Homogeneous Limit

详细信息    查看全文

• 作者：Michael P. CamposMark P. Hendricks ; Alexander N. Beecher ; Willem Walravens ; Robert A. Swain ; Gregory T. Cleveland ; Zeger Hens ; Matthew Y. SfeirJonathan S. Owen
• 刊名：Journal of the American Chemical Society
• 出版年：2017
• 出版时间：February 15, 2017
• 年：2017
• 卷：139
• 期：6
• 页码：2296-2305
• 全文大小：644K
• ISSN：1520-5126

文摘

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.