Improvement of 650-nm red-emitting GaIn0.17N/GaIn0.38N multiple quantum wells on ScAlMgO4 (0001) substrate by suppressing impurity diffusion/penetration

Autor: Ryo Takahashi, Ryoto Fujiki, Keisuke Hozo, Ryoya Hiramatsu, Makoto Matsukura, Takahiro Kojima, Dong-Pyo Han, Motoaki Iwaya, Tetsuya Takeuchi, Satoshi Kamiyama
Rok vydání: 2022
Předmět:
Zdroj: Applied Physics Letters. 120:142102
ISSN: 1077-3118
0003-6951
Popis: This study aims to improve the crystalline quality of 650-nm GaIn0.17N/GaIn0.38N red-emitting multiple quantum wells (MQWs) fabricated on a ScAlMgO4 (SCAM) substrate. When using the SCAM substrate, the diffusion and/or penetration of impurities, including Mg, Sc, O, and Al, from the SCAM substrate poses as a challenge. To address this issue, we introduced an Al0.74In0.26N layer between the SCAM substrate and MQWs, which was lattice-matched to the substrate. The Al0.74In0.26N layer effectively blocked the diffusion of impurities from the SCAM substrate into the adjacent layers during the metal-organic vapor epitaxy (MOVPE) growth. For further suppression, a thick AlN layer was deposited on the back of the SCAM substrate before the MOVPE growth, which effectively suppressed impurity penetration from the growth surface. The structure proposed in this study improved the crystallinity and the surface roughness of MQWs, resulting in the improvement of internal quantum efficiency by approximately three times compared to that of the conventional sample.
Databáze: OpenAIRE