Photoluminescence decay dynamics in γ-Ga2O3 nanocrystals: The role of exclusion distance at short time scales

• Published in: Chemical physics letters 2017-09, Vol.684, p.135-140
• Main Authors: Fernandes, Brian, Hegde, Manu, Stanish, Paul C., Mišković, Zoran L., Radovanovic, Pavle V.
• Format: Article
• Language: English
• Subjects: Defects; Donor-acceptor pair; Exclusion distance; Gallium oxide; Photoluminescence decay
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2017.06.052

[Display omitted] •We made analytical models of donor-acceptor defect interactions in Ga2O3 nanocrystals.•Defect sites were randomly distributed on the surface or throughout the nanocrystal.•Models are in good agreement with PL decay data for exclusion distance of ca. 1nm.•Exclusion distance between donor and acceptor plays a key role at short decay times.•The role of exclusion distance is independently confirmed by Monte Carlo simulations. We developed a comprehensive theoretical model describing the photoluminescence decay dynamics at short and long time scales based on the donor-acceptor defect interactions in γ-Ga2O3 nanocrystals, and quantitatively determined the importance of exclusion distance and spatial distribution of defects. We allowed for donors and acceptors to be adjacent to each other or separated by different exclusion distances. The optimal exclusion distance was found to be comparable to the donor Bohr radius and have a strong effect on the photoluminescence decay curve at short times. The importance of the exclusion distance at short time scales was confirmed by Monte Carlo simulations.