We present a detailed experimental study on the exciton dynamics in InGaAsN/GaAs quantum well structures after picosecond excitation. Time-resolved photoluminescence (PL) data are reported for samples grown in the very same conditions but differing for, the nitrogen content. By varying the excitation density and the lattice temperature, we show that the PL from samples with nitrogen arises from localized excitons. Besides, the emission from localized states saturates even at low excitation power with a broadening of the PL band on the high energy side. No major quenching of the quantum yield is observed upon temperature increase. This indicates that the recombination dynamics is affected by non-radiative channels, which do not strongly depend on temperature. The similar dynamics observed in nitrogenated and not-nitrogenated samples suggest the dominance of non-radiative channels due to the highly-strained host matrix.
Exciton dynamics in InGaAsN/GaAs heterostructures / A., Vinattieri; D., Alderighi; M., Zamfirescu; M., Colocci; Polimeni, Antonio; Capizzi, Mario; D., Gollub; M., Fischer; A., Forchel. - In: PHYSICA STATUS SOLIDI. A, APPLIED RESEARCH. - ISSN 0031-8965. - STAMPA. - 195:3(2003), pp. 558-562. [10.1002/pssa.200306152]
Exciton dynamics in InGaAsN/GaAs heterostructures
POLIMENI, Antonio;CAPIZZI, Mario;
2003
Abstract
We present a detailed experimental study on the exciton dynamics in InGaAsN/GaAs quantum well structures after picosecond excitation. Time-resolved photoluminescence (PL) data are reported for samples grown in the very same conditions but differing for, the nitrogen content. By varying the excitation density and the lattice temperature, we show that the PL from samples with nitrogen arises from localized excitons. Besides, the emission from localized states saturates even at low excitation power with a broadening of the PL band on the high energy side. No major quenching of the quantum yield is observed upon temperature increase. This indicates that the recombination dynamics is affected by non-radiative channels, which do not strongly depend on temperature. The similar dynamics observed in nitrogenated and not-nitrogenated samples suggest the dominance of non-radiative channels due to the highly-strained host matrix.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
