Quantum capture dynamics between different semiconductor quantum structures

不同半导体量子结构之间的量子捕获动力学

• 批准号: 11650020
• 负责人: FUJIWARA Kenzo
• 金额: $ 2.11万
• 依托单位: KYUSHU INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650020/
• 关键词: quantum well; photoluminescence; exciton; quantum capture; time-resolved emission; emission dynamics; radiative recombination lifetime; GaAs

In order to pursue mechanisms behind the competitive quantum capture processes of photogenerated carriers as a function of lattice temperature in electronically isolated semiconductor quantum wells with different well thicknesses, photoluminescence (PL) emission dynamics have been investigated and following results are obtained.1. Existence of quantum capture processes in PL emission spectraPicosecond time-resolved PL experiments have been undertaken in quantum well samples consisting of three or four different size wells. It is experimentally found that the lower energy emission bands show much weaker PL intensities than the higher energy ones, as opposed to the PL intensity distribution expected in thermal equilibrium conditions. The unique PL characteristics observed in several samples reflect the quantum capture processes and the dynamics exhibit, for example, much shorter PL lifetimes than the radiative recombination lifetimes.2. Temperature effects on quantum capture dynamicsIt i … More s experimentally demonstrated that the PL recombination dynamics originating from the observed competitive capture of photoexcited carriers between the quantum wells exhibit totally different temperature effects from the ones already known for the radiative recombination lifetimes of two dimensional excitons.3. Dependence of well width fluctuations on quantum capture dynamicsQuantum capture dynamics have been studied in composite GaAs quantum wells with monolayer growth island terraces, prepared by growth-interrupted molecular beam epitaxy. From detailed analysis of the PL results, it is newly discovered that the PL intensity distribution as well as the dynamics are both significantly influenced by relative energy positions of the first excited subband state to the barrier band edge. In addition, the transfer proceeses of excitons are confirmed between the island terraces.4. Mechanisms of quantum capture dynamics in composite quantum well systemsFrom comparison between two similar composite quantum well samples but with different configurations of outer clad layers (AlGaAs alloy and GaAs/AlAs superlattice digital alloy), it is found that both the PL intensity distribution and the dynamics including the temperature dependence are very different each other. These results suggest that mechanisms behind the quantum capture processes are sensitive to the subband energy structures of the clad layers, from which photogenerated carriers are distributed to the different wells with different subband energy structures. Less

为了探索不同厚度电子隔离半导体量子阱中光生载流子竞争量子俘获过程随晶格温度变化的机制，研究了光致发光(PL)发射动力学，得到了以下结果。光致发光光谱中量子俘获过程的存在-皮秒时间分辨光致发光实验已经在由三个或四个不同尺寸的势垒组成的量子井样品中进行。实验发现，与热平衡条件下预期的光致发光强度分布相反，低能发射带的发光强度比高能发射带弱得多。在几个样品中观察到的独特的发光特性反映了量子捕获过程，例如，动力学表现出比辐射复合寿命短得多的发光寿命。温度对量子俘获动力学的影响：It I…S进一步从实验上证明了光致发光复合动力学表现出与已知的二维激子辐射复合寿命完全不同的温度效应。量子俘获动力学研究了生长中断分子束外延制备的具有单层生长岛状平台的复合量子阱中的量子俘获动力学。通过对光致发光结果的详细分析，发现第一激发子带相对于势垒带边缘的相对能量位置对光致发光的强度分布和动力学都有显著的影响。此外，还证实了激子在岛台之间的转移过程。复合量子阱系统中量子俘获动力学机制通过比较两种不同外包层结构的复合量子井样品(AlGaAs合金和GaAs/AlAs超晶格数字合金)，发现它们的发光强度分布和动力学特性都有很大的不同，包括温度关系。这些结果表明，量子俘获过程背后的机制对包层的子带能量结构很敏感，光生载流子从包层分布到具有不同子带能量结构的不同势垒。较少

项目成果

K.Fujiwara, M.Ohe, M.Matsuo, T.Nogami, H.T.Grahn, K.H.Ploog: "Competitive capture dynamics of photogenerated carriers in a GaAs/Al_<0.17>Ga_<0.83>As triple quantum well with different well thicknesses"Institute of Physics Conference Series (Proceedings of

K.Fujiwara、M.Ohe、M.Matsuo、T.Nogami、H.T.Grahn、K.H.Ploog：“不同阱厚度的 GaAs/Al_<0.17>Ga_<0.83>As 三量子阱中光生载流子的竞争捕获动力学”

M.Matsuo, K.Sasayama, T.Nogami, K.Satoh, K.Fujiwara: "Exciton localization dynamics due to shallow and deep isoelectric traps in a triple GaAs quantum well grown by growth-interrupted molecular beam epitaxy"Proceedings of 11th Interantional Semiconducting

M.Matsuo、K.Sasayama、T.Nogami、K.Satoh、K.Fujiwara：“通过生长中断分子束外延生长的三重 GaAs 量子阱中浅层和深部等电陷阱导致的激子局域化动力学”第 11 届国际会议论文集

K.Fujiwara,H.T.Grahn,L.Schrottke and K.II.Ploog: "Photoexcitation-energy-dependent capture dynamics of excitons in electronically isolated GaAs quantum wells"Proceedings of 25th International Conference on the Physics of Semiconductors. (in print). (2001)

K.Fujiwara、H.T.Grahn、L.Schrottke 和 K.II.Ploog：“电子隔离 GaAs 量子阱中激子的光激发能量依赖捕获动力学”第 25 届国际半导体物理会议论文集。

K.Fujiwara,H.T.Grahn,L.Schrottke and K.II.Ploog: "Photoexcitation-energy-dependent capture dynamics of excitons in electronically isolated GaAs quantum wells"Proceedigns of 25th International Conference on the Physics of Semiconductors. (in print). (2001)

K.Fujiwara、H.T.Grahn、L.Schrottke 和 K.II.Ploog：“电子隔离 GaAs 量子阱中激子的光激发能量依赖捕获动力学”第 25 届国际半导体物理会议论文集。

K.Fujiwara, H.T.Grahn, L.Schrottke, K.H.Ploog: "Photoexcitation-energy-dependent capture dynamics of excitons in electronically isolated GaAs quantum wells"Proceedings of 25th International Conference on the Physics of Semiconductors, (Osaka, Japan, 2000)

K.Fujiwara、H.T.Grahn、L.Schrottke、K.H.Ploog：“电子隔离 GaAs 量子阱中激子的光激发能量依赖捕获动力学”第 25 届国际半导体物理会议论文集（日本大阪，2000 年）