Photoluminescence of m-plane GaN grown on m-plane sapphire by MOCVD

• Published in: Physica status solidi. C Vol. 11; no. 3-4; pp. 778 - 781
• Main Authors: Paduano, Qing S., Weyburne, David W., Look, David C.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.02.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Activation energy; Band spectra; Defects; Emission; Excitation; Gallium nitrides; nitride; Photoluminescence; Sapphire; stacking faults
• ISSN: 1862-6351; 1610-1642
• DOI: 10.1002/pssc.201300328

The photoluminescence of m‐plane GaN grown on m‐plane sapphire substrate by MOCVD is reported. The defect related emissions with temperature and excitation power dependence are detailed. In addition to the near band‐edge emission (at ∼3.472 eV), two major defect‐related bands (D1∼3.43 eV and D2∼3.34 eV) are dominant in the low temperature spectra. The D1 emission exhibits thermal quenching with two activation energies (8 and 30 meV), similar to that of a‐plane GaN grown on r‐plane sapphire. The D2 band was found to consist of a complex overlap of multiple emissions. By fitting the asymmetric band using multiple Gaussian functions, the extracted emission at ∼3.34 eV was shown to have thermal activation energy ∼17–20 meV. This emission exhibits different behavior from that of D2 in a‐plane GaN in temperature and excitation power dependency, indicating the possible involvement of different defects due to the changes in growth characteristics. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)