Elsevier, Physica B: Condensed Matter, 23-24(404), p. 5170-5172
DOI: 10.1016/j.physb.2009.08.275
Full text: Unavailable
The electro-optical properties of InAs/GaAs quantum dots (QD) are presented. It is shown that they can contribute to the photocurrent at temperatures where photo-generated excitons can split. This happens if the carrier binding energies are not too large to prevent the carrier emission process. At lower temperatures, the exciton recombination process can effectively compete with the carrier emission processes and no photocurrent signal is observed. The Laplace DLTS technique has been used in a wide temperature range to analyze the electron and hole emission separately and combine them with the observed temperature dependence of the photocurrent. The photocurrent measurements also showed that with an increase in temperature the dot-related photocurrent peaks shift to lower energies with a rate similar to GaAs band gap shrinkage.