| Project/Area Number |
17360138
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Shizuoka University |
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Principal Investigator |
HARA Kazuhiko Shizuoka University, Research Institute of Electronics, Professor (80202266)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥12,960,000 (Direct Cost: ¥12,600,000、Indirect Cost: ¥360,000)
Fiscal Year 2007: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2006: ¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 2005: ¥6,600,000 (Direct Cost: ¥6,600,000)
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| Keywords | Gallium nitride / Aluminum nitride / Fine crystalline particle / Hetero-structure / Vapor phase synthesis / Photoluminescence / Cathodoluminescence / X線回折 |
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| Research Abstract |
In contrast to the conventional powder phosphors consisting of particles with a uniform material composition, GaN-based nanostructure-embedded particles, which consist of GaN quantum dots or quantum wells in the AlN matrix, has been proposed to have higher luminescence efficiencies owing to the carrier confinement effect. As a fundamental technique to fabricate such particles, the following three processes have been demonstrated by using the vapor phase method.
(1) The AlN particles were first formed by a reaction of vaporized Al and N_2 gas at temperatures (T_1) from 1100 to 1250℃ in the first reactor. Although the sample prepared at 1100℃ is a mixture of AlN particles and unreacted Al, those prepared at T_1 higher than 1150℃ are a single phase AlN. It was found that the reaction temperature of 1200℃ is favorable from a viewpoint of producing the high quality AlN particles.
(2) At the second step, GaN was grown on the AlN core particles by a reaction of GaCl and NH_3 at 1000℃ in the second reactor. It can be seen that the particle diameter was increased from 0.1-0.2 μm for the AlN core. Thus fabricated GaN/AlN bilayer particles showed cathodoluminescence dominated by the band edge emission of GaN, indicating a high crystalline quality of the overgrown GaN.
(3) AlN was deposited on the surface of GaN particles by a reaction of AlCl_3 and NH_3 in the downstream part of the second reactor. AlN-coated particle showed photoluminescence (PL) dominated by the band edge emission of GaN. The dependence of AlCl_3 supply rate on the PL property suggests the effects of surface barrier to the excited carriers and passivation to surface defects.
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