Control of fine-structure splitting and biexciton binding inInxGa1−xAsquantum dots by annealing

Abstract

The distribution of the fine-structure splitting $\ensuremath{\Elzxh}{\ensuremath{\delta}}_{1}$ and of the biexciton binding energy $\ensuremath{\Elzxh}{\ensuremath{\delta}}_{B}$ are measured in a series of annealed InAs quantum dots. We find a decrease of $\ensuremath{\Elzxh}{\ensuremath{\delta}}_{1}$ from $96\ensuremath{\mu}\mathrm{eV}$ to $6\ensuremath{\mu}\mathrm{eV}$ with increasing annealing temperature, indicating a symmetrizing of the in-plane confinement potential. The biexciton binding energy shows only a weak dependence on the confinement energy, which we attribute to a compensation between decreasing confinement and decreasing separation of electron and hole.