465803 Substitutional Doping in Nanocrystal Superlattice

Wednesday, November 16, 2016: 4:41 PM
Golden Gate 5 (Hilton San Francisco Union Square)
Matteo Cargnello1, Aaron Johnston-Peck2, Benjamin T. Diroll3, Eric Wong4, Bianca Datta4, Divij Damodar4, Vicky Doan-Nguyen4, Andrew A. Herzing5, Cherie R. Kagan6 and Christopher B. Murray7, (1)Chemical Engineering, Stanford University, Stanford, CA, (2)National Institute of Standards and Technology, Gaithersburg, MD, (3)Department of Chemistry, University of Pennsylvania, Philadelphia, PA, (4)University of Pennsylvania, Philadelphia, PA, (5)Surface and Microanalysis Science Division, National Institute of Standards and Technology, Gaithersburg, (6)Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, (7)Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA

Doping, a process in which atomic impurities are intentionally added to modify the electronic properties of a semiconductor, has revolutionized our world, making computers, transistors, detectors, solar cells and other devices possible. Artificial atoms, nanocrystals (NC) with electronic properties dictated by their size and shape, have also emerged as technologically important materials. In this contribution, we introduce the concept of nanocrystal (NC) doping by merging the two above mentioned concepts. We show that, by matching the size of monodisperse gold nanocrystals (Au NCs) with that of semiconducting nanocrystals of cadmium selenide (CdSe) or lead selenide (PbSe) quantum dots (QDs), it is possible to purposely dope the semiconductor superlattices and induce novel properties in these self-assembled materials. We demonstrate that, comparably to the case of atomic doping, the Au NCs take random positions in the superlattice and their concentration can be tuned over a wide range. We show that the electronic and optical properties of the superlattices are affected by the presence of the Au dopants, which increase the conductivity and the photoconductivity of bare CdSe films by several orders of magnitude. We anticipate that this approach can originate a wide variety of NC-doped structures with applications in several fields including electronic materials, solar cells, sensors and catalysis.

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See more of this Session: Semiconducting Nanocrystals and Quantum Dots
See more of this Group/Topical: Materials Engineering and Sciences Division