Detection of magnetic resonance on shallow donor-shallow acceptor and deep (2.2 eV) recombination from GaN films grown on 6H-SiC
- Naval Research Lab., Washington, DC (United States)
- Sachs Freeman Associates, Landover, MD (United States)
- North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering
Photoluminescence (PL) and optically-detected magnetic resonance (ODMR) experiments have been performed on undoped GaN epitaxial layers growth on 6H-SiC substrates. The defects observed in these films are compared with those found from previous ODMR studies of undoped GaN layers grown on sapphire substrates. Strong, sharp donor-bound exciton bands at 3.46--3.47 eV and weak, broad emission bands at 2.2 eV were observed from several 0.7 and 2.6 {micro}m-thick films. In addition, fairly strong shallow donor-shallow acceptor (SD-SA) recombination with a zero-phonon-line at 3.27 eV was found for GaN layers less than 1 {micro}m-thick. The first observation of magnetic resonance on this SD-SA recombination from undoped GaN is reported in this work. Two magnetic resonance features attributed to effective-mass (EM) and deep-donor (DD) states were detected on the 2.2 eV emission bands from all the GaN/6H-SiC films. These resonances were observed previously on similar emission from undoped GaN layers grown on sapphire substrates. The same EM donor resonance, though much weaker, was also found on the SD-SA recombination. However, a resonance associated with shallow acceptor states was not observed on this emission. The weakness of the donor resonance arises from the weak spin-dependence of the recombination mechanism involving spin-thermalized shallow acceptors. The absence of an EM acceptor is due to the broadening of the resonance through the spreading of the acceptor g-values by random strains in these films.
- OSTI ID:
- 395019
- Report Number(s):
- CONF-951155-; ISBN 1-55899-298-7; TRN: IM9648%%96
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Gallium nitride and related materials; Ponce, F.A. [ed.] [Xerox Palo Alto Research Center, CA (United States)]; Dupuis, R.D. [ed.] [Univ. of Texas, Austin, TX (United States)]; Nakamura, S. [ed.] [Nichia Chemical Industries, Tokushima (Japan)]; Edmond, J.A. [ed.] [Cree Research, Inc., Durham, NC (United States)]; PB: 993 p.; Materials Research Society symposium proceedings, Volume 395
- Country of Publication:
- United States
- Language:
- English
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