Enhanced efficiency of near-UV LEDs by surface plasmon and magnetic field effects from metal films
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The enhanced efficiency of the near-UV (NUV) LEDs was demonstrated by the combinatory effects of surface plasmons (SP)from the Ag p-electrode and out-of-plane magnetic fields from additional Co/Pt multi-layers. By utilizing an InGaN/GaNbasedNUV-LED epilayer including either 100 or 40 nm p-GaN layers, four different flip-chip LEDs were fabricated byselectively adding Co/Pt ferromagnetic multi-layers on the Ag p-electrode. NUV-LEDs with Co/Pt ferromagnetic multi-layerson 100-nm-thick p-GaN showed a 10.1% enhancement of integrated electroluminescence (EL) intensity at a forward currentof 20 mA, mainly due to the out-of-plane magnetic field effect. In LEDs with a 40 nm p-GaN layer, which is consistent withthe penetration depth of SP fields, a further increase of 13.8% can be achieved in the integrated EL intensity at 20 mA,resulted from the additional coupling effect with SP fields. These results indicate that the combination of Ag and Co/Pt multilayers,as the p-electrode of flip-chip LEDs, can increase the efficiency in NUV flip-chip LEDs due to efficient couplings of SPfields and an out-of-plane magnetic field with carriers injected into quantum wells.
Abstract
The enhanced efficiency of the near-UV (NUV) LEDs was demonstrated by the combinatory effects of surface plasmons (SP)from the Ag p-electrode and out-of-plane magnetic fields from additional Co/Pt multi-layers. By utilizing an InGaN/GaNbasedNUV-LED epilayer including either 100 or 40 nm p-GaN layers, four different flip-chip LEDs were fabricated byselectively adding Co/Pt ferromagnetic multi-layers on the Ag p-electrode. NUV-LEDs with Co/Pt ferromagnetic multi-layerson 100-nm-thick p-GaN showed a 10.1% enhancement of integrated electroluminescence (EL) intensity at a forward currentof 20 mA, mainly due to the out-of-plane magnetic field effect. In LEDs with a 40 nm p-GaN layer, which is consistent withthe penetration depth of SP fields, a further increase of 13.8% can be achieved in the integrated EL intensity at 20 mA,resulted from the additional coupling effect with SP fields. These results indicate that the combination of Ag and Co/Pt multilayers,as the p-electrode of flip-chip LEDs, can increase the efficiency in NUV flip-chip LEDs due to efficient couplings of SPfields and an out-of-plane magnetic field with carriers injected into quantum wells.
참고문헌 (26)
- P. Waltereit, , Nature, 406, pp.865~868 (2000)
- A. Khan, , Nat. Photon, 2, pp.77~84 (2008)
- T. Wang, , Appl. Phys. Lett, 81, pp.2508~2510 (2002)
- A. Knauer, , Appl. Phys. Lett, 92, pp.191912~ (2008)
- A. Yasan, , Appl. Phys. Lett, 83, pp.4701~4703 (2002)
- Ki-Ryong Song, "Comparative study of InGaN", GaN multi-quantum wells in polar (0001) and semipolar (11-22) GaN-based light emitting diodes, 2012, pp.13, 295~299[DOI]
- semipolar InGaN, "GaN light emitting diodes grown on hemi-spherically patterned SiO2 mask", Journal of Ceramic Processing Research, 14(4), pp.521~524 (2013), 청정에너지연구소[DOI]
- M. Kunzer, , Phys. Stat. Sol, 4, pp.2822~2825 (2007)
- S. Watanabe, , Appl. Phys. Lett, 83, pp.4906~4908 (2003)
- A. Laubsch, , IEEE Trans. Electron Devices, 57, pp.79~87 (2010)
- A. M. Ficher, , Appl. Phys. Express, 2, pp.041002~ (2009)
- M. Peter, , Phys. Stat. Sol. A, 206, pp.1125~1129 (2009)
- K. Okamoto, , Nat. Mater, 3, pp.601~605 (2004)
- M. K. Kwon, , Adv. Mater, 20, pp.1253~1257 (2008)
- D. M. Yeh, , Appl. Phys. Lett, 9, pp.171103~ (2007)
- H. S. Chen, , Appl. Phys. Lett, 102, pp.041108~ (2013)
- C. Y. Cho, , Appl. Phys. Express, 5, pp.122103~ (2012)
- C. Y. Cho, , Appl. Phys. Lett, 98, pp.051106~ (2011)
- J. J. Kim, , ACS Photonics, 2, pp.1519~1523 (2015)
- B. Arnaudov, , Appl. Phys. Lett, 83, pp.2590~2592 (2003)
- Q. X. Zhao, , Phys. Rev. B, 50, pp.7514~7517 (1994)
- J. Lee, , J. Electrochem. Soc, 142(6), pp.90~92 (1995)
- S. R. Ragsdale, , J. Phys. Chem, 100, pp.5913~5922 (1996)
- M. Shao, , Adv. Mater, 23, pp.2216~2220 (2011)
- J. D. Jackson, "Classical Electrodynamics", pp.191~194 (1999), John Wiley & Sons Inc
- S. Emori, , J. Appl. Phys, 110, pp.033919~033911 (2011)[DOI]