Exciton localization behaviour in different well width undoped GaN/Al 0.07Ga0.93N nanostructures
2007 (English)Article in journal (Refereed) Published
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. © Association of Polish Electrical Engineers 2007.
Place, publisher, year, edition, pages
2007. Vol. 15, no 3, 163-167 p.
National CategoryNatural Sciences
IdentifiersURN: urn:nbn:se:liu:diva-38756DOI: 10.2478/s11772-007-0017-5Local ID: 45527OAI: oai:DiVA.org:liu-38756DiVA: diva2:259605