Step-like photoluminescence dynamics in field-effect structures containingquantum dots

We present time-resolved photoluminescence investigations of field-effect s tructures containing quantum dots (QDs). The high electrical field in those devices significantly influences carrier dynamics, Photoluminescence (PL) from the ground state occurs at an energy of 1.35 eV, but after strong exci tation the PL band can reach up to 1.5 eV due to state filling. After stron g excitation, a few hundred picoseconds of slow PL decay are observed. Then the emission from the QDs performs a step-like quenching. The remaining lu minescence has a long lifetime (about 1 ns) and its maximum occurs at about 1.35 eV. Numerical calculations suggest that the step-like PL quenching is caused by a decay of screening of the electrical field in the region with QDs.