Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, Minnesota 55455, USA.
Nat Commun. 2013;4:2197. doi: 10.1038/ncomms3197.
Colloidal semiconductor nanocrystals have attracted attention for cost-effective, solution-based deposition of quantum-confined thin films for optoelectronics. However, two significant challenges must be addressed before practical nanocrystal-based devices can be realized. The first is coping with the ligands that terminate the nanocrystal surfaces. Though ligands provide the colloidal stability needed to cast thin films from solution, these ligands dramatically hinder charge carrier transport in the resulting film. Second, after a conductive film is achieved, doping has proven difficult for further control of the optoelectronic properties of the film. Here we report the ability to confront both of these challenges by exploiting the ability of silicon to engage in hypervalent interactions with hard donor molecules. For the first time, we demonstrate the significant potential of applying the interaction to the nanocrystal surface. In this study, hypervalent interactions are shown to provide colloidal stability as well as doping of silicon nanocrystals.
胶体半导体纳米晶体因其在光电领域中具有成本效益且可溶液处理的量子限制薄膜沉积能力而备受关注。然而，在实际的基于纳米晶体的器件能够实现之前，必须解决两个重大挑战。第一个挑战是应对终止纳米晶体表面的配体。虽然配体为从溶液中铸造薄膜提供了所需的胶体稳定性，但这些配体极大地阻碍了薄膜中载流子的输运。其次，在获得导电薄膜后，掺杂对于进一步控制薄膜的光电性能证明是困难的。在这里，我们通过利用硅与硬施主分子形成高键合相互作用的能力来应对这两个挑战。我们首次证明了将这种相互作用应用于纳米晶体表面的巨大潜力。在这项研究中，高键合相互作用被证明提供了胶体稳定性和硅纳米晶体的掺杂。
