Exciton localization in vertically and laterally coupled GaN/AlN quantum dots.
Near-field and time-resolved photoluminescence measurements show evidence of exciton localization in vertically and laterally coupled GaN quantum dots (QDs). The binding energies in multiple period QDs (MQDs) are observed to be stronger by more than six times compared to single period QDs (SQDs). Excitons in MQDs have a short (450 ps) lifetime and persist at room temperature, while SQDs exhibit extraordinarily long (>5 ns) lifetime at 10 K due to reduced spatial overlap of electron and hole wave functions in strained QDs.
Neogi
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A
Department of Physics, University of North Texas, Denton, TX 76203, USA. arup@unt.edu
Morkoç
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H
Kuroda
T
T
Tackeuchi
A
A
Kawazoe
T
T
Ohtsu
M
M
D017607:Aluminum Compounds / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D016880:Anisotropy; D003460:Crystallization / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D005708:Gallium / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D036103:Nanotechnology / Q000379:methods*; D010777:Photochemistry / Q000379:methods; D045663:Quantum Dots; D011829:Radiation Dosage
D017607:Aluminum Compounds; C473348:gallium nitride; C052045:aluminum nitride; D005708:Gallium