Abstract
Absorption spectra of individual InGaAs quantum dots located within a diode structure are measured over a wide temperature range using photocurrent techniques. Strong saturation of the absorption with increasing excitation laser power is observed at low temperature whereas a nearly linear power dependence is measured at in a wide range of incident powers. The observed suppression of the saturation is a result of the pronounced broadening of the absorption peak due to a faster hole escape from the ground state at elevated temperature. In addition, the consequent fast tunneling of the hole from the excited state is shown to lead to a further strong increase of the saturation power. The observation indicates that the electrical read out of the quantum dot population can be performed on a considerably faster time scale as the temperature is increased.
- Received 31 July 2003
DOI:https://doi.org/10.1103/PhysRevB.69.155323
©2004 American Physical Society