Study on emission mechanism of inhomogeneous III-nitride mixed crystal semiconductors from the point of view of spatial resolved spectroscopy

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420288
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Yamaguchi University
• Principal Investigator: Kurai Satoshi 山口大学, 理工学研究科, 助教 (80304492)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: AlGaN / GaInN / 混晶半導体 / カソードルミネッセンス / 顕微分光 / 量子井戸構造

Outline of Final Research Achievements

Si-doped AlGaN epitaxial layers with different Al content and Si concentration has been studied by cathodoluminescence (CL) mapping. The surface hillocks increased with increasing Si concentration and with decreasing Al content, and local donor-acceptor-pair emission related to Si impurities occurred at hillock edges. Despite the crystallinity was high at higher Al contents, the spot CL linewidths were broader than the calculated linewidth from alloy broadening model at higher Al contents. This dependence indicated that the Al vacancy clusters acted as the origin of the additional line broadening at higher Al contents. The relation between microscopic distribution of luminescence and internal quantum efficiency of AlGaN multiple quantum wells was made clear.
Further, the potential profile around threading dislocations of GaInN epitaxial layers were qualitatively discussed from the temperature dependent CL mapping results.

Free Research Field

半導体工学