Versatile and Quantitative Spectrometer of Nonradiative recombination centers by Using Two-Wavelength Excitation method

双波长激发法非辐射复合中心多功能定量光谱仪

• 批准号: 14350002
• 负责人: KAMATA Norihiko
• 金额: $ 4.35万
• 依托单位: Saitama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350002/
• 关键词: photoluminescence; nonradiative recombination center; GaN; UV-and blue-light emitting materials; quantum well; quantum dot; 量子井戸構造

We exemplified the following research results during the project :(1)By combining a tunable below-gap excitation source (Optical Parametric Oscillator) and a sensitive CCD camera etc., we realized more versatile system of two-wavelength excited photoluminescence(TWEPL) for wider materials.(2)Inserting buffer layers with sufficient thickness, increasing quantum-well periods and utilizing modulation-doping were found to be effective for improving light emission efficiency through the characterization of GaN/AlGaN quantum wells grown by plasma-assisted MBE in Hannover University (Germany) and by our MOCVD technique.(3)We observed directly the formation of a trap-level due to an UV light irradiation during the measurement. The BGE effect after the trap formation was explained well by our two-levels model.(4)First detection of nonradiative centers in an InAs quantum dot has been done. Its temperature dependence is important for analyzing carrier dynamics in the quantum dot. In addition, a new trap level in a Y_2O_2S:Eu phosphor was resolved clearly by combining TWEPL with thermo-luminescence technique.Thus our TWEPL spectrometer became a versatile way to characterize belowgap states in wider range of light emitting materials.

在本课题中，我们取得了以下研究成果：（1）将可调谐的带隙下激发源（光学参量振荡器）和灵敏的CCD相机等相结合，我们实现了更广泛的材料的双波长激发光致发光（TWEPL）的多功能系统。（2）通过对德国汉诺威大学等离子体辅助分子束外延生长的GaN/AlGaN量子威尔斯阱和我们的MOCVD技术的表征，发现插入足够厚度的缓冲层、增加量子阱周期和利用调制掺杂可以有效地提高发光效率。(3)We直接观察到由于测量期间的UV光照射而形成的陷阱能级。我们的两能级模型很好地解释了陷阱形成后的BGE效应。（4）首次对InAs量子点中的非辐射中心进行了探测。它的温度依赖性对于分析量子点中的载流子动力学是重要的。此外，将TWEPL技术与热释光技术相结合，清晰地分辨出Y_2O_2S：Eu荧光粉中的一个新陷阱能级，从而使TWEPL光谱仪成为一种用于更广泛发光材料的能隙以下态表征的通用手段。

项目成果

H.Klausing, N.Kamata, T.Someya, Y.Arakawa et al.: "Improved quality of plasma assisted MBE-grown GaN/AlGaN quantum wells revealed by two-wavelength excited photoluminescence"Phys.Stat.Sol. (c). 0. 2658-2661 (2003)

H.Klausing、N.Kamata、T.Someya、Y.Arakawa 等人：“通过双波长激发光致发光揭示等离子体辅助 MBE 生长的 GaN/AlGaN 量子阱的质量得到改善”Phys.Stat.Sol。

N.Kamata, J.M.Z.Ocampo, T.Someya, Y.Arakawa et al.: "Improved quality of plasma assisted MBE-grown GaN/AlGaN quantum wells revealed by two-wavelength excited photoluminescence"Int. Conf. on Nitride Semiconductors 2003. (to be presented).

N.Kamata、J.M.Z.Ocampo、T.Someya、Y.Arakawa 等人：“通过双波长激发光致发光揭示了等离子体辅助 MBE 生长的 GaN/AlGaN 量子阱的质量提高”Int。

Formation of Eu^<2+> in SiO_2 Al_2O_3 Glass During Thermal Treatment in Sol-Gel Process

溶胶-凝胶法热处理过程中SiO_2 Al_2O_3玻璃中Eu^<2>的形成

• 发表时间: 2004
• 期刊: Jpn.J.Appl.Phys. 43
• 作者: N.Kamata;K.Tosaka;Z.Honda;K.Yamada
• 通讯作者: K.Yamada

Temperature dependence of photoluminescence intensity change due to below-gap excitation in GaN

GaN 中带隙下激发引起的光致发光强度变化的温度依赖性

• 发表时间: 2002
• 期刊: Inst.Phys.Conf.Ser. No.170
• 作者: N.Kamata;J.M.Z.Ocampo;T.Someya
• 通讯作者: T.Someya

N.Kamata, H.Klausing, T.Someya, Y.Arakawa et al.: "Effect of modulation-doping on luminescence properties of plasma assisted MBE-grown GaN/AlGaN quantum well"The European Phys.J.-Applied Physics. (in Print). (2004)

N.Kamata、H.Klausing、T.Someya、Y.Arakawa 等人：“调制掺杂对等离子体辅助 MBE 生长的 GaN/AlGaN 量子阱发光特性的影响”欧洲物理杂志-应用物理学。