Carrier dynamics in GaAs/AlAs ridge quantum wire

GaAs/AlAs 脊量子线中的载流子动力学

• 批准号: 12650014
• 负责人: NAKANISHI Shunsuke
• 金额: $ 2.56万
• 依托单位: Kagawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650014/
• 关键词: Quantum Wire; Quantum Well; GaAs; AlAs; Photoluminescence spectrum; Photoluminescence lifetime

We have investigated the carrier dynamics in the GaAs/AlAs ridge quantum wire by the optical methods. We could solely perform the measurement of the fluorescence spectra and its lifetime.[Experimental]We used the SHG of the femtosecond output pulse from a Ti:Sapphire regenerative Amp. (λ=400nm, 100μJ, 150fs) as the excitation. The samples studied here were the quantum wells, A1458 (AlAs 10nm-GaAs 7nm-AlAs 3nm), A1472 (AlAs 5nm-Al_<0.5>Ga_<0.5>As 170nm-GaAs 6nm-Al_<0.5>Ga_<0.5>As 170nm-AlAs 5nm), A1480 (AlAs 3nm-Al_<0.3>Ga_<0.7>As 283nm-GaAs 6nm-AlAs 3nm) and the ridge quantum wire with the same layer structure. The lifetime measurement of the fluorescence from the sample (10K) was carried out by using a streak camera.[Experimental Results](1) Lifetime measurement in GaAs/AlAs quantum wellsIn the case of strong excitation, we observed the broad fluorescence spectrum. It probably results from that the lowest excited states in quantum well are saturated due to the high density of the excited carriers. In this case, the lifetime was shorter at the shorter wavelength. In the case of weak excitation, we observed the narrow spectrum from the extitons in the quantum well. The measured lifetimes were 1290ps(A1458), 427ps(A1472), 280ps(A1480), respectively. In the sample A1480, the fluorescence at 666 nm of the barrier (Al_<0.3>Ga_<0.7>As) was also observed.(2) Lifetime measurement in GaAs/AlAs ridge quantum wireWe measured the lifetime of fluorescence in A1480 ridge sample. Two peaks were observed at 678 and 725 nm in the fluorescence spectrum. The lifetime of fluorescence was measured to be very short for the wavelength of 660 nm, but to become relatively long at 680 nm. At 700 nm, the fluorescence showed the two-exponential decay and it became the single-exponential deay at 720 nm. At 740 nm, the lifetime was observed to be long again. Based on these measurement, we attribute the fluorescence peaks at 678 nm and 725 nm to side-QW and QWR, respectively.

我们用光学方法研究了GaAs/AlAs脊型量子线中的载流子动力学。我们可以单独进行荧光光谱及其寿命的测量。[实验]我们使用了钛宝石再生放大器输出的飞秒脉冲的倍频。(λ=400 nm，100μJ，150fs)作为激发光。A1458(AlAs 10 nm-GaAs7 nm-AlAs 3 nm)、A1472(AlAs 5 nm-Al_&lt；0.5&gt；Ga_&lt；0.5&gt；As 170 nm-GaAs6 nm-Al_&lt；0.5&gt；As 170 nm-AlAs 5 nm)、A1480(AlAs 3 nm-Al_&lt；0.3&gt；Ga_&lt；0.7&gt；As 283 nm-GaAs6 nm-AlAs 3 nm)和脊型量子线。用扫描相机测量了样品(10K)的荧光寿命.[实验结果](1)在强激发下，我们观察到了较宽的荧光光谱.这可能是由于高密度的激发载流子导致量子阱中最低激发态饱和的结果。在这种情况下，波长越短，寿命越短。在弱激发的情况下，我们观察到量子阱中激子的窄谱。测得的寿命分别为1290ps(A1458)、427ps(A1472)、280ps(A1480)。在样品A1480中，还观察到了666 nm处的势垒(Al_&lt；0.3&Gt；Ga_&lt；0.7&Gt；As)的荧光。(2)GaAs/AlAs脊型量子线的寿命测量。荧光光谱在678和725 nm处观察到两个峰。在660 nm处，荧光寿命很短，在680 nm处，荧光寿命变得相对较长。在700 nm处，荧光呈双指数衰减，在720 nm处为单指数衰减。在740 nm处，观察到其寿命再次变长。基于这些测量，我们分别将678 nm和725 nm的荧光峰归因于Side-QW和QWR。

项目成果

Aguma, Asaka, Nakanishi, Itoh, et al.: "Optical detection system using time structure of UVSDR for combined laser-SR experiments"Nuclear Instruments & Methods in Physics Research. 467-468. 1455-1457 (2001)

Aguma、Asaka、Nakanishi、Itoh 等人：“使用 UVSDR 时间结构进行激光-SR 组合实验的光学检测系统”Nuclear Instruments

J. Azume, S. Asaka, T. Tsujibayashi, M. Itoh, M. Watanabe, O. Arimoto, S. Nakanishi, H. Itoh and M. Kamada: "Optical detection system using time structure of UVSOR for combined laser-SR experiments"Nuclear Instruments & Methods in Physics Research A. 467-

J. Azume、S. Asaka、T. Tsujibayashi、M. Itoh、M. Watanabe、O. Arimoto、S. Nakanishi、H. Itoh 和 M. Kamada：“使用 UVSOR 时间结构进行组合激光-SR 的光学检测系统

Azuma, Asaka, Nakanishi, Itoh, et al.: "Optical detection system using time structure of UVSOR for combined lases-SR experiments"Nuclear Instruments & Methods in Physics Research. 467-468. 1455-1457 (2001)

Azuma、Asaka、Nakanishi、Itoh 等人：“使用 UVSOR 时间结构进行组合激光-SR 实验的光学检测系统”Nuclear Instruments