Influence of substrate orientation on exciton fine structure splitting of InAs/InP nanowire quantum dots
Instytut Fizyki, UMK, Grudzia̧dzka 5, Toruń, 87-100, Poland
Nanoscale Research Letters 2012, 7:265 doi:10.1186/1556-276X-7-265Published: 22 May 2012
In this paper, we use an atomistic approach to investigate strain distributions, single particle and many body electronic properties of InAs/InP nanowire quantum dots with substrate orientation varying from  to high-index , and compared with  case. We show that single particle gap for high-index [11k] substrates is increased with respect to  and  cases, and oscillates with the substrate index due to faceting effects. Surprisingly, the overall shell-like structure of single particle states is preserved even for highly facetted, high-index substrates. On the contrary, we demonstrate that besides two limiting high-symmetry cases,  and , the bright exciton splitting varies strongly with substrate orientation. For -oriented substrate, the fine structure splitting reaches maximum due to crystal lattice anisotropy despite fully cylindrical isotropic shape of nanowire quantum dot.