Three-dimensional GaN dodecagonal ring structures for highly efficient phosphor-free warm white light-emitting diodes
| Autor: | Young Chul Sim, Seung-Hyuk Lim, Hyun Gyu Song, Yang-Seok Yoo, Sunghan Choi, Hwanseop Yeo, Min-Ho Jang, Sang-Won Lee, Kie Young Woo, Yong-Hoon Cho |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science business.industry Phosphor Gallium nitride 02 engineering and technology Color temperature 021001 nanoscience & nanotechnology Ring (chemistry) Indium gallium nitride 01 natural sciences chemistry.chemical_compound chemistry 0103 physical sciences White light Optoelectronics Energy transformation General Materials Science 0210 nano-technology business Diode |
| Zdroj: | Nanoscale. 10:4686-4695 |
| ISSN: | 2040-3372 2040-3364 |
| Popis: | Warm and natural white light (i.e., with a correlated colour temperature 75) is in demand as an indoor lighting source of comfortable interior lighting and mood lighting. However, for warm white light, phosphor-converted white light-emitting diodes (WLEDs) require a red phosphor instead of a commercial yellow phosphor (YAG:Ce3+), and suffer from limitations such as unavoidable energy conversion losses, degraded phosphors and high manufacturing costs. Phosphor-free WLEDs based on three-dimensional (3D) indium gallium nitride (InGaN)/gallium nitride (GaN) structures are promising alternatives. Here, we propose a new concept for highly efficient phosphor-free warm WLEDs using 3D core–shell InGaN/GaN dodecagonal ring structures, fabricated by selective area growth and the KOH wet etching method. Electrically driven, phosphor-free warm WLEDs were successfully demonstrated with a low correlated colour temperature (4500 K) and high colour rendering index (Ra = 81). From our findings, we believe that WLEDs based on dodecagonal ring structures become a platform enabling a high-efficiency warm white light-emitting source without the use of phosphors. |
| Databáze: | OpenAIRE |
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