Spectroscopic Study on Inverse Auger Effect of Semiconductor Quantum Dots

半导体量子点反俄歇效应的光谱研究

• 批准号: 18550024
• 负责人: TAMAI Naoto
• 金额: $ 2.64万
• 依托单位: Kwansei Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18550024/
• 关键词: Inverse Auger Effect; Semiconductor Quantum Dots; Single-Photon Timing; Auger Effect; Transient Absorption Spectroscopy; Single Particle Spectroscopy; オージェ効果; 発光寿命

Various sized CdTe QDs were synthesized in organic and water solvents, and the precursors were removed by several methods. Steady-state luminescence spectra were examined as a function of excitation wavelength, and the spectral shape of QDs was found to be independent of the wavelength, suggesting the free from an impurity. The second (400nm) and third (266nm) harmonics of femtosecond Ti:sapphire laser were used as excitation pulse to measure the luminescence decay and analyze inverse Auger effect.By using various sized CdTe QDs, we found that inverse Auger effect was observed when ω/Eg is larger than 2.5, in which the lifetime becomes shorter and multicarriers are formed in single CdTe QDs. For 5.4nm sized CdTe QDs (Eg=1.73 eV), the quantum efficiency of inverse Auger effect was 190%. In addition, the effective mass of the electron and hole may play an important role on the threshold energy of 2.5Eg for inverse Auger effect of CdTe QDs. Excitation intensity dependence of transient absorption dynamics was also examined to reveal Auger effect of CdTe QDs that is due to the interaction of muliticarriers generated by inverse Auger effect. The Auger effects of CdTe QDs and nanowires can be analyzed by the time-dependent recombination rate by Global analysis and the Auger recombination rate of nanowires was found to be larger than that of QDs. Furthermore, the excitation intensity dependence in single particle spectroscopy revealed that the Auger ionization plays an dominant role for the blinking dynamics of CdTe QDs.

在有机和水溶液中合成了各种大小的CDTE QD，并通过多种方法去除前体。检查了稳态发光光谱作为兴奋波长的函数，发现QD的光谱形状与波长无关，这表明没有杂质。 The second (400nm) and third (266nm) harmonics of femtosecond Ti:sapphire laser were used as excitement pulse to measure The luminescence decay and analyze inverse Auger effect.By using various sized CdTe QDs, we found that inverse Auger effect was observed when ω/Eg is larger than 2.5, in which the lifetime becomes shorter and multicarriers are formed in single CdTe QDs.对于5.4nm尺寸的CDTE QD（例如= 1.73 eV），反向螺旋臂效应的量子效率为190％。另外，电子和孔的有效质量可能在2.5EG的阈值能量上起重要作用，对于CDTE QD的逆促螺旋效应。还检查了瞬态吸收动力学的激发强度依赖性，以揭示CDTE QD的螺旋钻效应，这是由于抗螺旋体效应产生的穆里氏载体的相互作用所致。可以通过全局分析的时间依赖性重组率来分析CDTE QD和纳米线的螺旋螺旋效应，并且发现纳米线的螺旋钻重组速率比QD的螺旋钻重组速率大。此外，单个颗粒光谱中的兴奋强度依赖性表明，螺旋螺旋电离对于CDTE QD的闪烁动力学起主要作用。

项目成果

Fluorescence lifetime standards for time and frequency domain fluorescence spectroscopy

• DOI: 10.1021/ac062160k
• 发表时间: 2007-03-01
• 期刊: ANALYTICAL CHEMISTRY
• 影响因子: 7.4
• 作者: Boens, Noel;Qin, Wenwu;Miura, Atsushi
• 通讯作者: Miura, Atsushi

Nonlinear optical properties of thiol-capped CdTe quantum dots in nonresonant region

• DOI: 10.1063/1.2761494
• 发表时间: 2007-07-30
• 期刊: APPLIED PHYSICS LETTERS
• 影响因子: 4
• 作者: Pan, Lingyun;Tamai, Naoto;Deki, Shigehito
• 通讯作者: Deki, Shigehito

Spectroscopy and Dynamics of Semiconductor Quantum Dots and Nanowires by Microspectroscopy

显微光谱学研究半导体量子点和纳米线的光谱学和动力学

• 发表时间: 2006
• 作者: N. Tamai;L. Pan;J. Nakayama;Y. Miyoshi;A. Mandal
• 通讯作者: A. Mandal

Detection of optical trapping of CdTe quantum dots by two-photon-induced luminescence

• DOI: 10.1103/physrevb.75.161305
• 发表时间: 2007-04-01
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Pan, Lingyun;Ishikawa, Atsushi;Tamai, Naoto
• 通讯作者: Tamai, Naoto

Nonlinear Optical Properties and Single Particle Spectroscopy of CdTe Quantum Dots

CdTe 量子点的非线性光学性质和单粒子光谱

• 发表时间: 2008
• 期刊: Photochemistry 39
• 作者: 不動寺浩;澤田勉;S. Hashimoto;Seiichi Furumi;S. Hashimoto;D. Werner;橋本修一;Zhifei Dai;Abhijit Mandal;T. Sanjoy Singh;Yoichi Kobayashi
• 通讯作者: Yoichi Kobayashi