Electronic and optical properties of InAs∕InP quantum dots on InP(100) and InP(311)B substrates: Theory and experiment

Abstract

We study the electronic and optical properties of $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}$ quantum dots (QDs) on (100) and $\left(311\right)B$ substrates. Atomic force microscopy (AFM) and cross-sectional scanning tunneling microscopy (X-STM) are used to define the size and shape of the quantum dots for calculations. Eight-band $\mathbf{k}\mathbf{\bullet }\mathbf{p}$ calculations including strain and piezoelectric effects are then performed on such a structure for two different kinds of substrate orientation $\left(311\right)B$ and (100). Results for several QD heights found on $\left(311\right)B$ substrate fit well the experimental data obtained from photoluminescence measurements. On $\left(311\right)B$ substrate, the shear and hydrostatic deformations are found to be enhanced compared to those on (100) substrate thus affecting the electronic and optical properties. The $\left(311\right)B$ QDs are found to activate second-order ($S\text{−}P$ channels) transitions resulting from the complete loss of symmetry due to the presence of the piezoelectric field.