PHYS 211 |
| Doping - the intentional introduction of impurities - is critical for controlling the properties of bulk semiconductors. This has motivated efforts to dope semiconductor nanocrystals. While a variety of doped nanocrystals have been synthesized, no detailed understanding existed about how this process worked. Moreover, it was not clear why impurities could be introduced into some nanocrystals but not into others. Here we discuss a new model based upon kinetics that addresses the doping problem. We show that: (i) the nanocrystal surface plays a key role in the doping process and (ii) the surfactants in the growth solution can inhibit doping by competitively binding with the impurity. We then use our model to incorporate Mn into previously undopable CdSe nanocrystals. This success establishes that earlier difficulties are not intrinsic, and that a variety of doped nanocrystals - for applications from solar cells to bio-imaging - can be anticipated. |
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Spectroscopy, Chemistry, and Imaging through Nanophotonics
8:00 AM-12:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 345, Oral
Division of Physical Chemistry |