Strain-Induced Quenching of Optical Transitions in Capped Self-Assembled Quantum Dot Structures

Abstract

Strain-induced quenching of optical transitions has been found in capped self-assembled quantum dot structures. Light absorption at the ${\mathrm{E}}_1$ and $E_1+{\Delta }_1$ critical points of InSb islands buried in InP disappears for nominal InSb thicknesses lower than 10 monolayers as a consequence of the strain produced inside the islands by the cap layer. Certainly, this strain increases as the InSb deposition diminishes, changing the band lineup of the system from type-I to type-II and therefore drastically reducing the oscillator strengths of the island-related ${\mathrm{E}}_1$ and ${\mathrm{E}}_1+{\Delta }_1$ transitions.