Development of bright red light-emitting devices by elucidation and control of light-emitting mechanism in rare-earth-doped nitride semiconductors

2016 Fiscal Year Final Research Report

• Project/Area Number: 24226009
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Electronic materials/Electric materials
• Research Institution: Osaka University
• Principal Investigator: FUJIWARA Yasufumi 大阪大学, 工学研究科, 教授 (10181421)
• Co-Investigator(Kenkyū-buntansha): 吉田 博 大阪大学, 基礎工学研究科, 教授 (30133929) ; 小泉 淳 大阪大学, 工学(系)研究科(研究院), 助教 (30418735) ; 児島 貴徳 大阪大学, 工学(系)研究科(研究院), 助教 (70725100) ; 寺井 慶和 九州工業大学, 情報工学研究院, 教授 (90360049)
• Project Period (FY): 2012-05-31 – 2017-03-31
• Keywords: 電気・電子材料 / 薄膜 / 希土類元素 / 発光機能制御 / 発光ダイオード

Outline of Final Research Achievements

We succeeded in the development of a novel red light-emitting diode (LED) using Eu-doped GaN. The red emission is due to the intra-4f shell transitions of Eu3+ ions, which is different in a conventional red LED using AlGaInP/GaAs. In this study, in collaboration with computational materials design, we elucidated and controlled light-emitting mechanism of Eu ions through the GaN host for bright red emission. Energy transfer efficiency to Eu ions from the GaN host has been optimized by purposeful engineering of local structures around Eu ions. The coexistence of donor- and acceptor-like impurities/defects in the vicinity of Eu ions made the energy transfer drastically effective. Furthermore, the Eu emission was greatly enhanced in nanostructures. Based on these findings, we were able to prepare an optimized bright LED with the nanostructure as an active layer, with the world record light output power of over 1 mW. Our LED is now ready for wide-scale industrial implementation.

Free Research Field

電気電子工学、電気電子材料工学