Observation of excitonic polariton and broadening of room-temperature exciton in strained InGaAs/GaAs quantum wells

Abstract

Photoluminescence and absorption spectra of strained InGaAs/GaAs single quantum well (SQW) and multiple quantum well (MQW) structures as a function of well width have been investigated in detail. It has been demonstrated that the strength of the exciton-LO phonon coupling is quite stronger in InGaAs/GaAs SQW structures than that of InGaAs/GaAs MQW structures by aid of the temperature-dependent linewidth analysis. The critical temperature for the excitonic polariton-mechanical exciton transition in InGaAs/GaAs quantum well structures is found to be ∼35 K.