Electrically modulated photoluminescence in self-organized InGaAs/GaAs quantum dots

Results of photoluminescence (PL) study of the self-organized InGaAs/GaAs quantum dots (QDs) in a field-effect structure grown by metalorganic vapor phase epitaxy are presented. It has been found that the PL from the QDs strongly depends on the bias voltage. No PL from the QDs ground state can be observed from the reverse biased structure, whereas the PL signal recovers in the forward biased structure. It is proposed that the bias dependence of the PL signal results from the QDs electron occupancy changes driven by the electric field within the structure. Due to a long thermalization time, the photogenerated electrons are swept out of the QDs by the electric field before radiative recombination. The electrically modulated PL (e-m PL), making use of the bias dependence of PL signal, is proposed as a tool for QD investigation. The e-m PL spectra at T=300 and T=4.2 K are analyzed and discussed. (C) 1998 American Institute of Physics. [S0003-6951(98)02345-6].