Nag, Angshuman and Chakraborty, Sudip and Sarma, DD (2008) To Dope Mn2+ in a Semiconducting Nanocrystal. In: Journal of the American Chemical Society, 130 (32). pp. 10605-10611.
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It has been an outstanding problem that a semiconducting host in the bulk form can be doped to a large extent, while the same host in the nanocrystal form is found to resist any appreciable level of doping rather stubbornly, this problem being more acute in the wurtzite form compared to the zinc blende one. In contrast, our results based on the lattice parameter tuning in a ZnxCd1−xS alloy nanocrystal system achieves 7.5% Mn2+ doping in a wurtzite nanocrystal, such a concentration being substantially higher compared to earlier reports even for nanocrystal hosts with the “favorable” zinc-blende structure. These results prove a consequence of local strains due to a size mismatch between the dopant and the host that can be avoided by optimizing the composition of the alloyed host. Additionally, the present approach opens up a new route to dope such nanocrystals to a macroscopic extent as required for many applications. Photophysical studies show that the quantum efficiency per Mn2+ ion decreases exponentially with the average number of Mn2+ ions per nanocrystal; en route, a high quantum efficiency of 25% is achieved for a range of compositions.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to American Chemical Society.|
|Department/Centre:||Division of Chemical Sciences > Solid State & Structural Chemistry Unit|
|Date Deposited:||04 Jun 2010 05:26|
|Last Modified:||19 Sep 2010 05:59|
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