Optical time-of-flight measurement of carrier diffusion and trapping in an InGaAs/InP heterostructure

Abstract

We have measured the diffusion and trapping of photoexcited hot carriers in an InGaAs/InP heterostructure using an optical time-of-fight technique with picosecond time resolution. The ambipolar diffusivity is found to decrease by an order of magnitude between 4 K and room temperature, and the efficiency of trapping of carriers into the well increases rapidly in the same temperature range. A mean trapping time of 4 ps is measured for a 50 Å well.