Recombination dynamics in self‐assembled InP/GaP quantum dots under high pressure

Abstract

We have investigated the recombination dynamics in self-assembled InP/GaP quantum dots by means of time-resolved photoluminescence measured at low temperatures between 2 and 100 K and high hydrostatic pressure up to 2 GPa. Due to the high-power levels for pulsed excitation, the quantum dot emission exhibits two components with typical decay times of 5 and 30 ns, corresponding to direct Γ -Γ and X -Γ interband recombination processes, respectively. These decay times appear to be independent of pressure. At a very low pressure of about 0.1 GPa the intensity of the dot emission drops abruptly relative to that of the wetting layer indicating a switching off of a carrier relaxation channel.

Evidence of type-I direct recombination in InP/GaP quantum dots via magnetoluminescence

“…Studies of the PL behavior of QDs under hydrostatic pressure also indicate that the light emission originates from direct band gap type-I heterointerface QDs. 14,15 This paper describes investigations of the radiative recombination in InP/GaP self-assembled QDs measured in high magnetic fields. Using magneto-PL spectroscopy the reduced effective mass is determined to have a value of 0.094m 0 expected for electron states associated with the InP ⌫ valley.…”