Spectroscopy of photoluminescence excitation of InAs/InGaAs/GaAs quantum dot array in 20–300 K temperature range

Detailed photoluminescence and photoluminescence excitation (PLE) studying in temperature range 20–300 K with variation of detection energy of selforganized InAs/InGaAs/GaAs quantum dots is presented in this work. PLE spectra analysis allowed us to identify two types of peaks. First type associated with excited-ground state transitions with high probability. Second corresponds to transitions from excited states to the ground state which probability is small, but significantly increased due to the effective relaxation of carriers with LO phonons. We discovered, that the QD distinctive dependence of the energy difference between peaks spectral positions corresponding to the ground and excited states on the ground state energy (i.e., on the quantum dots size) deviates as the temperature rises to 140–160 K, at which charge carrier transport between QD is activated.