Paul-Drude-Institut für Festkörperelektronik, Berlin, Germany.
Nanotechnology. 2011 Oct 14;22(41):415701. doi: 10.1088/0957-4484/22/41/415701. Epub 2011 Sep 14.
Channeling-enhanced electron energy-loss spectroscopy is applied to determine the polarity of ultra-small nitride semiconductor nanocolumns in transmission electron microscopy. The technique demonstrates some practical advantages in the nanostructure analysis, especially for feature sizes of less than 50 nm. We have studied GaN and (Al, Ga)N nanocolumns grown in a self-assembled way by molecular beam epitaxy directly on bare Si(111) substrates and on AlN buffer layers, respectively. The GaN nanocolumns on Si show an N polarity, while the (Al, Ga)N nanocolumns on an AlN buffer exhibit a Ga polarity. The different polarities of nanocolumns grown in a similar procedure are interpreted in terms of the specific interface bonding configurations. Our investigation contributes to the understanding of polarity control in III-nitride nanocolumn growth.
通道增强电子能量损失谱被应用于在透射电子显微镜中确定超小氮化物半导体纳米柱的极性。该技术在纳米结构分析中具有一些实际优势，特别是对于小于 50nm 的特征尺寸。我们已经分别在未覆盖的 Si(111)衬底和 AlN 缓冲层上通过分子束外延生长自组装 GaN 和(Al, Ga)N 纳米柱。在 Si 上生长的 GaN 纳米柱表现出 N 极性，而在 AlN 缓冲层上生长的(Al, Ga)N 纳米柱表现出 Ga 极性。我们通过特定的界面键合结构解释了在类似过程中生长的纳米柱具有不同极性的原因。我们的研究有助于理解 III-氮化物纳米柱生长中的极性控制。
