Abstract
We report results from optical spectroscopy such as photoluminescence (PL) and time resolved photo-luminescence (TRPL) techniques from different well width MOCVD grown GaN/Al0.07Ga0.93N MQW samples. There is evidence of localization at low temperature in all samples. The decay time of all samples becomes non-exponential when the detection energy is increased with respect to the peak of the emission. Localization of carriers (excitons) is demonstrated by the “S-shape” dependences of the PL peak energies on the temperature. The time-resolved PL spectra of the 3-nm well multi quantum wells reveal that the spectral peak position shifts toward lower energies as the decay time increases and becomes red-shifted at longer decay times. There is a gradient in the PL decay time across the emission peak profile, so that the PL process at low temperatures is a free electron-localized hole transition.
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Sabooni, M., Esmaeili, M., Haratizadeh, H. et al. Exciton localization behaviour in different well width undoped GaN/Al0.07Ga0.93N nanostructures. Opto-Electron. Rev. 15, 163–167 (2007). https://doi.org/10.2478/s11772-007-0017-5
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DOI: https://doi.org/10.2478/s11772-007-0017-5