Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221-0011, USA.
Nano Lett. 2010 Mar 10;10(3):880-6. doi: 10.1021/nl903547r.
Highly strained GaAs/GaP nanowires of excellent optical quality were grown with 50 nm diameter GaAs cores and 25 nm GaP shells. Photoluminescence from these nanowires is observed at energies dramatically shifted from the unstrained GaAs free exciton emission energy by 260 meV. Using Raman scattering, we show that it is possible to separately measure the degree of compressive and shear strain of the GaAs core and show that the Raman response of the GaP shell is consistent with tensile strain. The Raman and photoluminescence measurement are both on good agreement with 8 band k.p calculations. This result opens up new possibilities for engineering the electronic properties of the nanowires for optimal design of one-dimensional nanodevices by controlling the strain of the core and shell by varying the nanowire geometry.
高质量的具有高应变的 GaAs/GaP 纳米线，其 50nm 直径的 GaAs 核和 25nm GaP 壳。这些纳米线的光致发光出现在能量上显著偏离未应变 GaAs 自由激子发射能量 260meV 的位置。通过拉曼散射，我们表明可以分别测量 GaAs 核的压缩和剪切应变程度，并表明 GaP 壳的拉曼响应与拉伸应变一致。拉曼和光致发光测量均与 8 带 k.p 计算结果非常吻合。这一结果为通过改变纳米线几何形状来控制核和壳的应变，从而优化一维纳米器件的电子性质，开辟了新的可能性。
