Optical and acoustic phonon modes in strained InGaAs/GaAs rolled up tubes
Optical and acoustic phonon modes in strained InGaAs/GaAs rolled up tubes
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DOI：
10.1063/1.4714542
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发表时间：
2012-05-14
影响因子：
4
通讯作者：
Cros, A.
中科院分区：
文献类型：
--
作者：
Angelova, T.;Shtinkov, N.;Cros, A.
用拉曼散射方法研究了由In_（0.215）Ga_（0.785）As/GaAs交替层制成的不同直径的半导体管。研究了单个管的光学和声学声子模式，并与周围材料的特性进行了比较。管形成后，声子模式的频率相对于生长的材料和无序激活模式的偏移被观察到。通过变形势近似，频率偏移与管内的残余应变有关。结果与原子价力场模拟和X射线微区衍射测量结果吻合较好，并与X射线数据进行了比较，提出In 0.215 Ga 0.785 As的拉曼应变常数K = 0.65。在低频率范围内，声学模式双峰观察到的周围材料中不存在的管。它们显示了在卷起过程后形成周期性超晶格的明确证据，并深入了解了它们的界面质量。(C)2012年美国物理学会。[http：//dx.doi.org/10.1063/1.4714542]
Rolled-up semiconductor tubes of various diameters made of alternating In0.215Ga0.785As/GaAs layers have been investigated by means of Raman scattering. The optical and acoustic phonon modes of individual tubes have been studied and compared with the characteristics of the surrounding material. After tube formation, the frequency of the phonon modes shifts with respect to the as-grown material and disorder activated modes are observed. The frequency shifts are related to the residual strain in the tubes through the deformation potential approximation. Good agreement with atomistic valence force field simulations and x-ray micro-diffraction measurements is found. By comparison with x-ray data, a Raman strain constant K = 0.65 is proposed for In0.215Ga0.785As. In the low frequency range, acoustic mode doublets are observed on the tubes that are absent in the surrounding material. They show clear evidence of the formation of periodic superlattices after the rolling-up process, and give insight into the quality of their interfaces. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4714542]