Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands.
Nano Lett. 2012 Dec 12;12(12):6206-11. doi: 10.1021/nl303081m. Epub 2012 Nov 12.
We tune the emission wavelength of an InAsP quantum dot in an InP nanowire over 200 meV by depositing a SiO(2) envelope using plasma-enhanced chemical vapor deposition without deterioration of the optical quality. This SiO(2) envelope generates a controlled static strain field. Both red and blue shift can be easily achieved by controlling the deposition conditions of the SiO(2). Using atomistic empirical tight-binding calculations, we investigate the effect of strain on a quantum dot band structure for different compositions, shape, and crystal orientations. From the calculations, we estimate the applied strain in our experiment. This enables engineering of the band gap in nanowires with unprecedented possibilities to extend the application range of nanowire devices.
我们使用等离子体增强化学气相沉积（PECVD）方法在 InP 纳米线中沉积二氧化硅（SiO2）包层，从而在不降低光学质量的情况下，将 InAsP 量子点的发射波长调谐超过 200 毫电子伏特（meV）。这种 SiO2 包层会产生一个可控的静态应变场。通过控制 SiO2 的沉积条件，可以轻松实现红移和蓝移。我们使用原子经验紧束缚计算方法，研究了应变对不同成分、形状和晶体取向的量子点能带结构的影响。通过计算，我们估算了实验中的施加应变。这使得在纳米线中工程化带隙成为可能，为纳米线器件的应用范围带来了前所未有的扩展可能性。
