| Towards Performance Enhancement of InGaN/GaN LED by Exploring Localized Surface Plasmons |
| In-Hwan Lee |
| Chonbuk National University |
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Surface plasmons (SP) are coherent electron oscillations that exist at a metal-dielectric interface. Specifically, the SP in noble metal nano-particles (NP) embedded in a dielectric matrix is called localized surface plasmons (LSP). These LSP have been studied for applications in sensing, medical imaging, and surface enhanced spectroscopy. Recently, the LSP phenomena have attracted great interest in InGaN/GaN based light-emitting diode (LED) as the luminescence efficiency can be improved by the energy coupling (EC) of LSP with the active quantum well (QW) region of such LED [1]. According to the EC mechanism, when the metal nanostructure forming LSP is deposited in close proximity to the active layer of LED and the emission energy matches the LSP oscillation energy, excitons in the active layer of LED can transfer their energy directly to the LSP mode as well as emitting light at the active layer, rather than decay via radiative and nonradiative recombination channels in the semiconductor structure.
Recently, we reported on the properties of chemically synthesized Ag and Ag/SiO2 NP and the performance enhancement of LED coated with these NP [2]. The attractive feature of such NP is the possibility to increase and carefully regulate the NP density with consequent increase in the enhancement factor. This is in contrast to metal NP formed by annealing. Moreover, for core/shell Ag/SiO2 NP a very substantial improvement in performance stability was observed as compared to purely metal NP [3].
In this talk we describe the results of experimental and theoretical studies of optical properties and electric field distribution in Ag and Ag/SiO2 NP, and report on the EC of their LSP resonance with InGaN/GaN MQW. Also, we proposed the fabrication of NP embedded in InGaN/GaN based nanopillar LEDs.
Figure 1 PL spectra from the nanopillar, Ag and Ag/SiO2 NP embedded sample and its schematic structure (inset).
References:
[1] K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, A. Schere: Nat. Mater. 3 (2004) 601.
[2] L. W. Jang, D. W. Jeon, T. Sahoo, D. S. Jo, J. W. Ju, S. J. Lee, J. H. Baek, J. K. Yang, J. H. Song, A. Y. Polyakov, I. H. Lee: Opt. Exp. 20, 3 (2012) 2116.
[3] L. W. Jang, D. W. Jeon, M. Kim, J. W. Jeon, A. Y. Polyakov, J. W. Ju, S. J. Lee, J. H. Baek, J. K. Yang, I. H. Lee: Adv. Func. Mater. 22 (2012) 2728.
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| Acknowledgements : This research was supported by National Research Foundation of Korea(NRF) funded by Ministry of Science, ICT & Future Planning (2013R1A2A2A07067688, 2010-0019626) |
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