碲化铅胶体纳米晶体：合成、表征及多激子产生

PbTe colloidal nanocrystals: synthesis, characterization, and multiple exciton generation.

作者信息

Murphy James E, Beard Matthew C, Norman Andrew G, Ahrenkiel S Phillip, Johnson Justin C, Yu Pingrong, Mićić Olga I, Ellingson Randy J, Nozik Arthur J

机构信息

Center for Basic Sciences, National Renewable Energy Laboratory, Golden, Colorado 80401, USA.

出版信息

J Am Chem Soc. 2006 Mar 15;128(10):3241-7. doi: 10.1021/ja0574973.

DOI:10.1021/ja0574973

PMID:16522105

Abstract

We report an alternative synthesis and the first optical characterization of colloidal PbTe nanocrystals (NCs). We have synthesized spherical PbTe NCs having a size distribution as low as 7%, ranging in diameter from 2.6 to 8.3 nm, with first exciton transitions tuned from 1009 to 2054 nm. The syntheses of colloidal cubic-like PbSe and PbTe NCs using a PbO "one-pot" approach are also reported. The photoluminescence quantum yield of PbTe spherical NCs was measured to be as high as 52 +/- 2%. We also report the first known observation of efficient multiple exciton generation (MEG) from single photons absorbed in PbTe NCs. Finally, we report calculated longitudinal and transverse Bohr radii for PbS, PbSe, and PbTe NCs to account for electronic band anisotropy. This is followed by a comparison of the differences in the electronic band structure and optical properties of these lead salts.

摘要

我们报告了胶体PbTe纳米晶体（NCs）的另一种合成方法及其首次光学表征。我们合成了球形PbTe NCs，其尺寸分布低至7%，直径范围为2.6至8.3 nm，首次激子跃迁从1009 nm调谐至2054 nm。还报道了使用PbO“一锅法”合成胶体立方状PbSe和PbTe NCs。测量得出PbTe球形NCs的光致发光量子产率高达52±2%。我们还报告了首次观察到在PbTe NCs中单个光子吸收产生高效多激子产生（MEG）。最后，我们报告了计算得出的PbS、PbSe和PbTe NCs的纵向和横向玻尔半径，以解释电子能带各向异性。随后对这些铅盐的电子能带结构和光学性质的差异进行了比较。