Measurement of carrier concentration captured by InAs/GaAs quantum dots using terahertz time-domain spectroscopy

Abstract

The authors investigated the carrier dynamics of n-type modulation-doped InAs/GaAs quantum dots (QDs) using terahertz time-domain spectroscopy to estimate the total number of electrons captured by the QDs. The terahertz power absorption of the sample with QDs was less than that of the sample without QDs. This is attributed to the fact that the carriers are confined in the QDs. The experiment results were fitted into the Drude model and the number of electrons captured by QDs was determined through the difference in the numbers of free electrons of the samples with and without QDs. (c) 2007 American Institute of Physics.