General control of transition-metal-doped GaN nanowire growth: toward understanding the mechanism of dopant incorporation.
General control of transition-metal-doped GaN nanowire growth: toward understanding the mechanism of dopant incorporation.
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DOI：
10.1021/nl8009523
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发表时间：
2008-08
期刊：
影响因子：
10.8
通讯作者：
Kevin G. Stamplecoskie;L. Ju;S. S. Farvid-S.;P. Radovanovic
中科院分区：
文献类型：
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作者：
Kevin G. Stamplecoskie;L. Ju;S. S. Farvid-S.;P. Radovanovic
我们首次报道了钴和铬掺杂GaN纳米线的合成和表征，并将其与锰掺杂GaN纳米线进行了比较。样品通过化学气相沉积法合成，使用氯化钴（II）和氯化铬（III）作为掺杂剂前体。对于所有三种杂质掺杂剂六边形，三角形，和矩形的纳米线进行观察。具有特定形态的NW的分数取决于掺杂剂前体的初始浓度。虽然所有三种掺杂剂离子对GaN NW生长和刻面具有相同的效果，但Co和Cr以比Mn低得多的浓度并入。这些研究结果表明，掺杂机制涉及的过渡金属中间体结合到特定的NW方面，抑制它们的生长，并引起NW形态的变化。我们讨论了Mn，Co和Cr的掺杂浓度在其气相中间体和替代掺杂GaN纳米线中的晶体场稳定能（DeltaCFSE）的差异。使用氯化铁（III）和乙酸钴（II）作为掺杂剂前体，我们表明，掺杂浓度依赖于DeltaCFSE允许实现的掺杂浓度的预测不同的掺杂剂离子在GaN纳米线，并合理选择一个合适的掺杂剂离子前体。这项工作进一步证明了使用过渡金属杂质的GaN NW生长的一般和合理的控制。
We report the first synthesis and characterization of cobalt- and chromium-doped GaN nanowires (NWs), and compare them to manganese-doped GaN NWs. Samples were synthesized by chemical vapor deposition method, using cobalt(II) chloride and chromium(III) chloride as dopant precursors. For all three impurity dopants hexagonal, triangular, and rectangular NWs were observed. The fraction of NWs having a particular morphology depends on the initial concentration of the dopant precursors. While all three dopant ions have the identical effect on GaN NW growth and faceting, Co and Cr are incorporated at much lower concentrations than Mn. These findings suggest that the doping mechanism involves binding of the transition-metal intermediates to specific NW facets, inhibiting their growth and causing a change in the NW morphology. We discuss the doping concentrations of Mn, Co, and Cr in terms of differences in their crystal-field stabilization energies (DeltaCFSE) in their gas-phase intermediates and in substitutionally doped GaN NWs. Using iron(III) chloride and cobalt(II) acetate as dopant precursors we show that the doping concentration dependence on DeltaCFSE allows for the prediction of achievable doping concentrations for different dopant ions in GaN NWs, and for a rational choice of a suitable dopant-ion precursor. This work further demonstrates a general and rational control of GaN NW growth using transition-metal impurities.