Professor Andrew Turberfield

Abstract:

We report the first picosecond time-resolved photoluminescence measurementsof hot-carrier relaxation in a modulation-doped GaAs-GaAlAs MQW in the presence of strong magnetic fields. We have measured the lifetimes of carriers in excited Landau levels and have determined the time-dependent carrier temperature. We find that the cooling rate is slower in applied field tthan at B=0; also there is a significant increase in the cooling rate for B {greater-than or approximate} 10T. We report also the observation of highly time-dependent linewidths of the Landau levels. © 1985.

Abstract:

In this paper the authors show how picosecond time-resolved photoluminescence can be used to probe the energy relaxation of hot carriers in semiconductor structures. In addition, by measuring the variation of luminescence lifetime with carrier density one can obtain information about radiative and nonradiative decay processes. These processes are important in all photonic devices, but especially so in structures where interfaces may have a particularly strong influence.