Enhanced luminescence properties of InAs-InAsP core-shell nanowires.
Enhanced luminescence properties of InAs-InAsP core-shell nanowires.
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DOI：
10.1021/nl403341x
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发表时间：
2013-11
期刊：
影响因子：
10.8
通讯作者：
J. Treu;M. Bormann;H. Schmeiduch;M. Döblinger;S. Morkötter;S. Matich;P. Wiecha;K. Saller;B. Mayer;M. Bichler;M. Amann;J. Finley;G. Abstreiter;G. Koblmüller
中科院分区：
文献类型：
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作者：
J. Treu;M. Bormann;H. Schmeiduch;M. Döblinger;S. Morkötter;S. Matich;P. Wiecha;K. Saller;B. Mayer;M. Bichler;M. Amann;J. Finley;G. Abstreiter;G. Koblmüller
利用窄带隙纳米线（NW）材料将纳米光子应用扩展到中红外光谱区域（>2-3 μm）是非常有吸引力的，然而，由于非辐射表面和俄歇复合引起的低辐射效率，进展受到严重阻碍。在这里，我们证明了高达10（2）倍的增强发射强度从InAs纳米线生长的InAsP壳产生核-壳纳米线。通过系统地改变InAsP壳层的厚度和磷（P）含量，我们证明了通过在相对低的部分P含量下已经超过>100 meV的大应变诱导峰位移来进一步调谐发射能量的能力。通过横截面扫描透射电子显微镜证实，由于从{110}-到{112}-侧壁生长的独特转变产生的不对称壳生长，增加P含量会导致额外的线宽增宽。研究结果还阐明了塑性应变弛豫对发射特性的不利影响，特别是在具有非常高的P含量和壳厚度的核壳结构中。总的来说，我们的研究结果强调，增强中红外发射效率与有效的载流子限制和抑制非辐射复合是高度敏感的InAs-InAsP核壳界面的质量。
Utilizing narrow band gap nanowire (NW) materials to extend nanophotonic applications to the mid-infrared spectral region (>2-3 μm) is highly attractive, however, progress has been seriously hampered due to their poor radiative efficiencies arising from nonradiative surface and Auger recombination. Here, we demonstrate up to ~ 10(2) times enhancements of the emission intensities from InAs NWs by growing an InAsP shell to produce core-shell NWs. By systematically varying the thickness and phosphorus (P)-content of the InAsP shell, we demonstrate the ability to further tune the emission energy via large strain-induced peak shifts that already exceed >100 meV at comparatively low fractional P-contents. Increasing the P-content is found to give rise to additional line width broadening due to asymmetric shell growth generated by a unique transition from {110}- to {112}-sidewall growth as confirmed by cross-sectional scanning transmission electron microscopy. The results also elucidate the detrimental effects of plastic strain relaxation on the emission characteristics, particularly in core-shell structures with very high P-content and shell thickness. Overall, our findings highlight that enhanced mid-infrared emission efficiencies with effective carrier confinement and suppression of nonradiative recombination are highly sensitive to the quality of the InAs-InAsP core-shell interface.