Carrier Dynamic Investigations of AlGaInAs Quantum Well Revealed by Temperature-Dependent Time-Resolved Photoluminescence

Abstract

AlGaInAs quantum well (QW) lasers have great potential in the application fields of optical communications and eye-safety lidars, owing to the advantages of good gain performance. A large amount of experimental evidence indicated that carrier dynamic affects the resonant frequency and modulation response performance of QW lasers. However, the mechanism of carrier dynamic in AlGaInAs QW structure is still ambiguous for complicated artificial multilayers. In this paper, the carrier dynamic of AlGaInAs QW structure was investigated by temperature-dependent time-resolved photoluminescence (TRPL) in the range of 14 to 300 K. Two relaxation times (a fast component and a slow one) have a major impact on the PL emission spectra of the AlGaInAs QW below 200 K. The carriers prefer a fast decay channel in the low temperature regime, whereas the slow one a higher temperature. An unconventional temperature dependence of carrier relaxation is observed in both decay processes. The carriers’ lifetime decreases with the temperature increasing till 45 K and then increases with temperature up to 250 K. It is quite different from that in the bulk semiconductor. The mechanism of temperature-dependent carrier relaxation at temperatures above 45 K is a combination of dark state occupation and a nonradiative recombination process.