On the importance of antimony for temporal evolution of emission from self-assembled (InGa)(AsSb)/GaAs quantum dots on GaP(001)

TL;DR

This study investigates the optical properties and carrier dynamics of (InGa)(AsSb)/GaAs/GaP quantum dots, highlighting their potential for nano memory devices and quantum photonic applications due to their tunable emission characteristics.

Contribution

It provides a detailed analysis of carrier dynamics in (InGa)(AsSb)/GaAs/GaP quantum dots, emphasizing the role of antimony in emission properties and potential integration with CMOS technology.

Findings

Type-I emission with recombination times of 2-10 ns.

Coexistence of momentum direct and indirect QD transitions.

Emission blue-shift driven by charged-background effects.

Abstract

Understanding the carrier dynamics of nanostructures is the key for development and optimization of novel semiconductor nano-devices. Here, we study the optical properties and carrier dynamics of (InGa)(AsSb)/GaAs/GaP quantum dots (QDs) by means of non-resonant energy and temperature modulated time-resolved photoluminescence. Studying this material system is important in view of the ongoing implementation of such QDs for nano memory devices. Our set of structures contains a single QD layer, QDs overgrown by a GaSb capping layer, and solely a GaAs quantum well, respectively. Theoretical analytical models allow us to discern the common spectral features around the emission energy of 1.8 eV related to GaAs quantum well and GaP substrate. We observe type-I emission from QDs with recombination times between 2 ns and 10 ns, increasing towards lower energies. The distribution suggests the coexistence of momentum direct and indirect QD transitions. Moreover, based on the considerable tunability of the dots depending on Sb incorporation, we suggest their utilization as quantum photonic sources embedded in complementary metal-oxide-semiconductor (CMOS) platforms, since GaP is almost lattice-matched to Si. Finally, our analysis confirms the nature of the pumping power blue-shift of emission originating from the charged-background induced changes of the wavefunction topology.