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▲ [18p-Z33-4] The Electroluminescence of ZnO nanoparticle-based LEDs improved by inserting a ZnMgO nanoparticles layer.
Keywords:ZnO nanoparticles, Light Emitting Diode, Electroluminescence
Zinc Oxide (ZnO) with a room temperature direct band gap of 3.37 eV and a large exciton binding energy (60 meV), is one of the candidates to realize commercial ultraviolet (UV) emission devices. ZnO nanoparticle (NP) based light-emitting devices were prepared using a nitrogen-doped ZnO NP layer on GZO films by our group [1]. But, our device has large leakage current and problem of the diffusion of holes to GZO layer that has no luminescence due to very high electron concentration. Because ZnMgO acts as an energy barrier layer to confine the recombination processes [2], it can use to confine the holes to the active layer. In this study, we inserted the ZnMgO composite nanoparticles layer to overcome the problem.
In the research, we synthesized nitrogen-doped ZnO nanoparticles (NPs) by gas evaporation method [3]. ZnMgO composite nanoparticles were prepared using MgO NPs into ZnO NPs by thermal diffusion. The ZnMgO NPs layer was deposited on a GZO electrode by simple spray method. We prepared p-ZnO NPs solutions by mixing with a binder (Silsesquioxane) and coated on the ZnMgO NPs layer by spin coating. These layers were sintered by the hot plate at~ 300°C. Finally, the gold (Au) electrodes were evaporated with 30 nm thickness. We measured the properties of ZnO NP LEDs and compared the electroluminescence (EL) emission of LEDs with and without ZnMgO NPs layer. The leakage current was decreased and the EL intensity was enhanced by inserting a ZnMgO NPs barrier layer. Later, we will present the detailed of the results.
Reference
[1] Y. Fujita, K. Moriyama, Y. Hiragino, Y. Furubayashi, H. Hashimoto, and T. Yoshida, Phys. Status Solidi C11,1260 (2014). [2] J. H. Lim, C. K. Kang, K. K. Kim, I. K. Park, D. K. Hwang, and S. J. Park, Adv. Mater. 18(20), 2720–2724 (2006).
[3] Y. Fujita, Japanese patent No.4072620.
In the research, we synthesized nitrogen-doped ZnO nanoparticles (NPs) by gas evaporation method [3]. ZnMgO composite nanoparticles were prepared using MgO NPs into ZnO NPs by thermal diffusion. The ZnMgO NPs layer was deposited on a GZO electrode by simple spray method. We prepared p-ZnO NPs solutions by mixing with a binder (Silsesquioxane) and coated on the ZnMgO NPs layer by spin coating. These layers were sintered by the hot plate at~ 300°C. Finally, the gold (Au) electrodes were evaporated with 30 nm thickness. We measured the properties of ZnO NP LEDs and compared the electroluminescence (EL) emission of LEDs with and without ZnMgO NPs layer. The leakage current was decreased and the EL intensity was enhanced by inserting a ZnMgO NPs barrier layer. Later, we will present the detailed of the results.
Reference
[1] Y. Fujita, K. Moriyama, Y. Hiragino, Y. Furubayashi, H. Hashimoto, and T. Yoshida, Phys. Status Solidi C11,1260 (2014). [2] J. H. Lim, C. K. Kang, K. K. Kim, I. K. Park, D. K. Hwang, and S. J. Park, Adv. Mater. 18(20), 2720–2724 (2006).
[3] Y. Fujita, Japanese patent No.4072620.