Photoluminescence between 3.36 eV and 3.41 eV from GaN epitaxial layers
GaN, its alloys, QWs and MQWs have gained an important place among short-wavelength optical emitters and high temperature electronic devices. The performance of such devices is limited by the presence of native and impurity defects. The understanding of the optical properties of the basic material allows them to improve its quality and thus increase the performance of these materials. In non intentionally doped (nid) hexagonal good quality GaN layers grown on sapphire, 6H-SiC or Si, free exciton (FXC, FXB, FXA), donor bound exciton (DX), acceptor bound exciton (AX) and donor-acceptor pair (DAP) transitions have been reported by several authors. Besides these typical emissions, emission lines in the range 3.3--3.44 eV have been observed in nid and intentionally doped hexagonal GaN layers. However, the nature of these recombinations is not completely clarified. Some authors assigned them to a superposition of LO phonon assisted transitions of DX and FX, excitons bound to neutral donors with deeper donor levels, band to impurity transitions and/or free to bound emission involving oxygen, DAP transitions, shallow bound excitons of cubic phases, excitons bound to structural defects and Zn related recombinations. In this work the authors analyze the luminescence between 3.36 eV and 3.41 eV of nid hexagonal GaN samples grown on sapphire. They found sample dependent emission lines with no DAP behavior. From the data they are able to identify different kinds of recombination processes in the same spectral region.
- Research Organization:
- Univ. de Aveiro (PT)
- OSTI ID:
- 20104743
- Resource Relation:
- Conference: 1999 Materials Research Society Spring Meeting, San Francisco, CA (US), 04/05/1999--04/08/1999; Other Information: PBD: 1999; Related Information: In: Wide-band semiconductors for high-power, high-frequency and high-temperature applications -- 1999. Materials Research Society symposium proceedings: Volume 572, by Binari, S.C.; Burk, A.A.; Melloch, M.R.; Nguyen, C. [eds.], 575 pages.
- Country of Publication:
- United States
- Language:
- English
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