National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea.
Nat Mater. 2010 Jan;9(1):47-53. doi: 10.1038/nmat2572. Epub 2009 Nov 15.
Doping of semiconductor nanocrystals by transition-metal ions has attracted tremendous attention owing to their nanoscale spintronic applications. Such doping is, however, difficult to achieve in low-dimensional strongly quantum confined nanostructures by conventional growth procedures. Here we demonstrate that the incorporation of manganese ions up to 10% into CdSe quantum nanoribbons can be readily achieved by a nucleation-controlled doping process. The cation-exchange reaction of (CdSe)(13) clusters with Mn(2+) ions governs the Mn(2+) incorporation during the nucleation stage. This highly efficient Mn(2+) doping of the CdSe quantum nanoribbons results in giant exciton Zeeman splitting with an effective g-factor of approximately 600, the largest value seen so far in diluted magnetic semiconductor nanocrystals. Furthermore, the sign of the s-d exchange is inverted to negative owing to the exceptionally strong quantum confinement in our nanoribbons. The nucleation-controlled doping strategy demonstrated here thus opens the possibility of doping various strongly quantum confined nanocrystals for diverse applications.
由于其纳米尺度的自旋电子学应用，半导体纳米晶的过渡金属离子掺杂引起了极大的关注。然而，通过传统的生长程序，在低维强量子受限的纳米结构中很难实现这种掺杂。在这里，我们证明通过成核控制掺杂过程，很容易将锰离子掺入到 CdSe 量子纳米带中，达到 10%的浓度。(CdSe)(13) 团簇与 Mn(2+) 离子的阳离子交换反应控制着成核阶段的 Mn(2+)掺入。这种 CdSe 量子纳米带的高效 Mn(2+)掺杂导致了巨大的激子塞曼分裂，有效 g 因子约为 600，这是迄今为止在稀磁半导体纳米晶体中看到的最大数值。此外，由于我们的纳米带中存在异常强的量子限制，s-d 交换的符号被反转到负值。因此，这里展示的成核控制掺杂策略为各种强量子限制纳米晶体的掺杂提供了可能性，从而可应用于不同的领域。
