Transient carrier transfer in tunnel injection structures

Abstract

InGaAs tunnel injection nanostructures consisting of a single quantum well as injector and a quantum dot layer as emitter are studied by time-resolved photoluminescence spectroscopy. The quantum dot photoluminescence undergoes substantial changes when proceeding from direct quantum dot excitation to quantum well excitation, which causes an indirect population of the dot ground states. This results in a lowered effective carrier temperature within the dots. Results on the carrier transfer versus barrier thickness are discussed within the Wentzel-Kramers-Brillouin approximation. Deviations for barrier thicknesses <5 nm are assigned to the formation of nanobridges that are actually detected by transmission electron microscopy. © 2008 American Institute of Physics.