Share Email Print
cover

Proceedings Paper

Optical characteristics of hexagonal and cubic GaN self-assembled quantum dots
Author(s): Yong Hoon Cho; B. J. Kown; Julien Barjon; J. Brault; B. Daudin; Henri Mariette; Le Si Dang
Format Member Price Non-Member Price
PDF $17.00 $21.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Studies on the optical properties related to built-in internal electric field and carrier localization present in the GaN self-assembled quantum dots (QDs) are essential for the physical interest in atomic-like confined system and the visible and ultraviolet light emitting applications. We have systematically studied the optical properties of hexagonal GaN (h-GaN) and cubic GaN (c-GaN) self-assembled QDs by means of photoluminescence (PL), PL excitation (PLE), cathodoluminescence (CL), and time-resolved PL experiments. The GaN self-assembled QD samples were grown in Stranski-Krastanov mode by plasma-assisted molecular beam epitaxy. The substrates for the growth of h-GaN and c-GaN were 6H-SiC and 3C-SiC, respectively. With increasing temperature, the PL intensity of GaN quantum wells was dramatically decreased while that of GaN QDs was not changed much. From the wavelength-resolved CL images, strong carrier localization in the QD confinement was clearly observed. An apparent Stokes-like shift between PLE absorption edge and PL emission from the h-GaN QDs increases with increasing detection wavelength (so, with QD size), which is attributed to the separation of wavefunction overlap due to the built-in internal field present in the QDs. From the time-resolved PL experiments, we found that the measured lifetime of the h-GaN QDs emission increased with emission wavelength (i.e., with QD size), while that of the c-GaN QDs kept almost constant. It is concluded that the h-GaN QD emissions are strongly influenced by built-in internal electric field as well as carrier localization in the QDs.

Paper Details

Date Published: 16 June 2004
PDF: 8 pages
Proc. SPIE 5352, Ultrafast Phenomena in Semiconductors and Nanostructure Materials VIII, (16 June 2004); doi: 10.1117/12.526103
Show Author Affiliations
Yong Hoon Cho, Chungbuk National Univ. (South Korea)
B. J. Kown, Chungbuk National Univ. (South Korea)
Julien Barjon, CEA/CNRS (France)
LSP, CNRS, Univ. Joseph Fourier (France)
J. Brault, CEA/CNRS (France)
LSP, CNRS, Univ. Joseph Fourier (France)
B. Daudin, CEA/CNRS (France)
LSP, CNRS, Univ. Joseph Fourier (France)
Henri Mariette, CEA/CNRS (France)
LSP, CNRS, Univ. Joseph Fourier (France)
Le Si Dang, CEA/CNRS (France)
LSP/CNRS, Univ. Joseph Fourier (France)


Published in SPIE Proceedings Vol. 5352:
Ultrafast Phenomena in Semiconductors and Nanostructure Materials VIII
Kong-Thon Tsen; Jin-Joo Song; Hongxing Jiang, Editor(s)

© SPIE. Terms of Use
Back to Top