Correlation between structural and optical properties of single semiconductor nanowires with core-shell heterostructure

具有核壳异质结构的单根半导体纳米线的结构和光学性质之间的相关性

• 批准号: 175391613
• 负责人: Dr. Lutz Geelhaar
• 金额: --
• 依托单位: Paul-Drude-Institut für Festkörperelektronik (PDI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/175391613?language=en
• 关键词: Correlation; between; structural; optical; properties

Semiconductor nanowires have emerged as an important materials basis both for studying fundamental physics and for fabricating novel devices. In the nanowire geometry, strain can elastically relax at the free sidewalls, and thus heterostructures of dissimilar materials can be grown in a crystalline quality that is impossible to obtain in planar thin films. At the same time, the quasi one-dimensional shape, nanometric size, and high surface-to-volume ratio of nanowires can lead to unexpected effects. In order to understand, predict, and control the physical properties of nanowires, it is imperative to elucidate how the properties of interest depend on the nanowire structure. The overall objective of this project is to correlate the optical and structural properties of single GaAs nanowires with radial (In,Ga)As/GaAs quantum well. For such nanowire heterostructures a larger critical thickness for the formation of dislocations is expected than in their planar counterparts, because the strain induced by lattice mismatch is shared between (In,Ga)As quantum well and GaAs core and outer shell. Also, the optical transitions are anticipated to be different for the nanowire heterostructure, because the strain state of the quantum well is modified, the band structure is affected by lateral band bending due to Fermi level pinning at the nanowire sidewalls, and the nature of the entire structure is intrinsically three-dimensional.The ambitious experimental goal is to measure subsequently for one and the same single nanowire the optical and structural properties, and carry out such measurements for series of samples with systematic variations in structure. Samples will be grown by molecular beam epitaxy, the optical properties will be investigated by photo- and cathodoluminescence spectroscopy, and the structure will be analyzed by x-ray nanodiffraction. In order to obtain a deep understanding of the structure-property correlation, experiments will be complemented by continuum elasticity and multiband-k.p calculations of the optical transitions. We will identify the observed emission lines, assign them to structural features, and elucidate how these lines vary with In content and/or quantum well thickness.

半导体纳米线已经成为研究基础物理和制造新型器件的重要材料基础。在纳米线几何结构中，应变可以在自由侧壁弹性松弛，因此不同材料的异质结可以生长出平面薄膜中不可能获得的结晶质量。与此同时，纳米线的准一维形状、纳米尺寸和高比表面积比可能会导致意想不到的效果。为了理解、预测和控制纳米线的物理性质，必须阐明感兴趣的性质是如何依赖于纳米线结构的。本项目的总体目标是将单根GaAs纳米线与径向(In，Ga)As/GaAs量子阱的光学和结构特性关联起来。对于这种纳米线异质结，位错形成的临界厚度比平面异质结大，因为晶格失配引起的应变在(In，Ga)As量子阱和GaAs核壳之间共享。此外，对于纳米线异质结构，光学跃迁预计将不同，因为量子阱的应变态被改变，能带结构受到纳米线侧壁费米能级钉扎引起的横向能带弯曲的影响，并且整个结构本质上是三维的。雄心勃勃的实验目标是随后测量一根相同的纳米线的光学和结构性质，并对结构发生系统变化的一系列样品进行这种测量。样品将通过分子束外延生长，光学性质将通过光致发光和阴极发光光谱进行研究，结构将通过X射线纳米衍射进行分析。为了深入了解结构与性质的关系，将用光学跃迁的连续弹性和多带K.P计算来补充实验。我们将识别观察到的发射线，将它们分配给结构特征，并阐明这些线如何随着含量和/或量子阱厚度的变化而变化。

项目成果

Determination of indium content of GaAs/(In,Ga)As/(GaAs) core-shell(-shell) nanowires by x-ray diffraction and nano x-ray fluorescence

• DOI: 10.1103/physrevmaterials.2.014604
• 发表时间: 2018-01-19
• 期刊: PHYSICAL REVIEW MATERIALS
• 影响因子: 3.4
• 作者: Al Hassan, Ali;Lewis, R. B.;Pietsch, U.
• 通讯作者: Pietsch, U.

Threefold rotational symmetry in hexagonally shaped core–shell (In,Ga)As/GaAs nanowires revealed by coherent X-ray diffraction imaging

相干 X 射线衍射成像揭示六边形核壳 (In,Ga)As/GaAs 纳米线的三重旋转对称性

• DOI: 10.1107/s1600576717004149
• 发表时间: 2017
• 期刊: Journal of Applied Crystallography
• 影响因子: 6.1
• 作者: A. Davtyan;T. Krause;D. Kriegner;A. Al-Hassan;D. Bahrami;S.M. Mostafavi Kashani;R.B. Lewis;H. Küpers;A. Tahraoui;L. Geelhaar;M. Hanke;S.J. Leake;O. Loffeld;U. Pietsch
• 通讯作者: U. Pietsch

Anomalous Strain Relaxation in Core-Shell Nanowire Heterostructures via Simultaneous Coherent and Incoherent Growth.

• DOI: 10.1021/acs.nanolett.6b03681
• 发表时间: 2017-01
• 期刊: Nano letters
• 影响因子: 10.8
• 作者: R. Lewis;Lars Nicolai;H. Küpers;M. Ramsteiner;A. Trampert;L. Geelhaar

Surface preparation and patterning by nano imprint lithography for the selective area growth of GaAs nanowires on Si(111)

• DOI: 10.1088/1361-6641/aa8c15
• 发表时间: 2017-11-01
• 期刊: SEMICONDUCTOR SCIENCE AND TECHNOLOGY
• 影响因子: 1.9
• 作者: Kuepers, Hanno;Tahraoui, Abbes;Geelhaar, Lutz
• 通讯作者: Geelhaar, Lutz

Characterization of individual stacking faults in a wurtzite GaAs nanowire by nanobeam X-ray diffraction

通过纳米束 X 射线衍射表征纤锌矿 GaAs 纳米线中的单个堆垛层错

• DOI: 10.1107/s1600577517009584
• 发表时间: 2017
• 期刊: Journal of Synchrotron Radiation
• 影响因子: 2.5
• 作者: A. Davtyan;S. Lehmann;D. Kriegner;R.R. Zamani;K.A. Dick;D. Bahrami;A. Al- Hassan;S.J. Leake;U. Pietsch;V. Holý
• 通讯作者: V. Holý