Spatial cross section of local and non-local upconversion processes for upconversion in InAs based quantum structures

TL;DR

This paper investigates the spatial and temporal dynamics of upconversion processes in InAs quantum structures, highlighting the roles of local and non-local mechanisms through experimental transient photoluminescence data.

Contribution

It provides new insights into the spatial energy transfer cross section and distinguishes local and non-local upconversion processes in InAs quantum structures.

Findings

Quantum structures are key sources of upconversion.

Both local and non-local processes contribute to upconversion.

Time constants suggest monolayer InAs structures are crucial.

Abstract

Transients of upconverted photoluminescence (UPL) from molecular beam epitaxy (MBE) grown InAs quantum structures have been obtained. The results indicate the importance of spatial energy transfer cross section in the upconversion processes. The time constants determined suggest that several monolayer (ML) thick InAs quantum structures are the origin of upconversion. Both the time resolved and continuous wave data allow for the discussion of the dynamic balance between a local process (for example excitonic Auger process) and non-local process (for example two-step two-photon-absorption process with photon recycling) in such a system.