A comparative study of the internal quantum efficiency for the green MQWs grown on sapphire and FS‐GaN substrates

Autor: Chang-Hee Hong, Hae-Yong Lee, Eun-Kyung Suh, Jong-Pil Jeong, Jae Young Park, Yong-Hee Jeong
Rok vydání: 2007
Předmět:
Zdroj: physica status solidi c. 4:187-191
ISSN: 1610-1642
1862-6351
DOI: 10.1002/pssc.200673528
Popis: We observed the green MQWs grown on FS-GaN substrates leading to less generation of dislocation, V-defect, and stacking fault than those on sapphire by AFM and TEM. The temperature-dependent PL spectral peak energies of the green MQWs grown on FS-GaN substrates reveal more clear “S”-shaped behaviors due to stronger carrier localization than those on sapphire substrates. Also, the green MQWs grown on FS-GaN have the higher internal quantum efficiency (IQE) of 9 ∼ 12% in compared to those grown on sapphire at the same MQW thickness and wavelength of 530 ∼ 540 nm. These results will be due to the effects of the enhanced carrier localization and the reduced quantum confined stark effect (QCSE) by reason of the optical-loss reduction as decreasing the defect density and the piezoelectric field reduction as decreasing the relaxation of strain. We could identify that the green MQWs grown on FS-GaN substrates have the superior characteristics of the optics, structure, and surface to those on sapphire substrates. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Databáze: OpenAIRE
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