GaN quantum dots in Al{sub x}Ga{sub 1{minus}x}N confined layer structures
- Inst. of Physical and Chemical Research, Saitama (Japan)
Nanoscale GaN quantum dots were fabricated in Al{sub x}Ga{sub 1{minus}x}N confined layer structures via metalorganic chemical vapor deposition (MOCVD), by using a surfactant which can modify the GaN growth mode on AlGaN surfaces. A two dimensional growth mode (step-flow-like) of GaN films on Al{sub x}Ga{sub 1{minus}x}N (x = 0--0.2) surfaces, that is energetically commenced under the conventional growth conditions, was intentionally changed into a three dimensional mode by adding tetraethyl-silane (TESi) used as a surfactant onto the AlGaN substrate surface prior to the GaN deposition. The surfactant is believed to inhibit the GaN film from wetting the AlGaN surface due to the change in surface free energy. The resulting morphological structures of GaN dots were found to be sensitive to; the doping rate of TESi, the Al content (x) of the Al{sub x}Ga{sub 1{minus}x}N layer, and the growth temperature. A very intense photoluminescence (PL) emission was observed from the GaN dots embedded in the AlGaN layers. The quantum size effect in terms of the blue-shift in a PL peak position was verified using the GaN dot samples having different dot sizes.
- OSTI ID:
- 580985
- Report Number(s):
- CONF-961202--; ISBN 1-55899-353-3
- Country of Publication:
- United States
- Language:
- English
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