Phosphor-Free InGaN White Light Emitting Diodes Using Flip-Chip Technology
| Autor: | Chia-Yi Yen, Dan Zhou, Ewa Popko, Lee Chow, Ke-Wei Pan, Hou-Jen Chen, Wen-Yu Kuo, Ying-Chang Li, Liann-Be Chang, Bohr-Ran Huang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
quantum well chemistry.chemical_element Gallium nitride Phosphor 02 engineering and technology Color temperature Indium gallium nitride 01 natural sciences lcsh:Technology Article law.invention chemistry.chemical_compound phosphor free law 0103 physical sciences General Materials Science lcsh:Microscopy lcsh:QC120-168.85 010302 applied physics lcsh:QH201-278.5 business.industry lcsh:T quantum dot 021001 nanoscience & nanotechnology Solid-state lighting InGaN/GaN chemistry Quantum dot lcsh:TA1-2040 white LED Optoelectronics lcsh:Descriptive and experimental mechanics lcsh:Electrical engineering. Electronics. Nuclear engineering 0210 nano-technology business lcsh:Engineering (General). Civil engineering (General) lcsh:TK1-9971 Indium Light-emitting diode |
| Zdroj: | Materials; Volume 10; Issue 4; Pages: 432 Materials, Vol 10, Iss 4, p 432 (2017) Materials |
| ISSN: | 1996-1944 |
| DOI: | 10.3390/ma10040432 |
| Popis: | Monolithic phosphor-free two-color gallium nitride (GaN)-based white light emitting diodes (LED) have the potential to replace current phosphor-based GaN white LEDs due to their low cost and long life cycle. Unfortunately, the growth of high indium content indium gallium nitride (InGaN)/GaN quantum dot and reported LED's color rendering index (CRI) are still problematic. Here, we use flip-chip technology to fabricate an upside down monolithic two-color phosphor-free LED with four grown layers of high indium quantum dots on top of the three grown layers of lower indium quantum wells separated by a GaN tunneling barrier layer. The photoluminescence (PL) and electroluminescence (EL) spectra of this white LED reveal a broad spectrum ranging from 475 to 675 nm which is close to an ideal white-light source. The corresponding color temperature and color rendering index (CRI) of the fabricated white LED, operated at 350, 500, and 750 mA, are comparable to that of the conventional phosphor-based LEDs. Insights of the epitaxial structure and the transport mechanism were revealed through the TEM and temperature dependent PL and EL measurements. Our results show true potential in the Epi-ready GaN white LEDs for future solid state lighting applications. |
| Databáze: | OpenAIRE |
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