通过负电荷的刺激子观察电荷传输
D Sanvitto1, F Pulizzi, A J Shields
1Toshiba Research Europe Limited, Cambridge Research Laboratory, 260 Cambridge Science Park, Milton Road, Cambridge, CB4 0WE, UK.
Science (New York, N.Y.)
|September 29, 2001
概括
我们观察到负电荷的激子 (X-),在应用电场时,可以在半导体量子井中漂移. 这种受控的激子运动为光电子设备开辟了新的可能性.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 量子光学是一种量子光学.
背景情况:
- 电子孔复合体,如激子,是半导体光学性质的基础.
- 了解量子井中的激子动态对于开发先进的光电子设备至关重要.
- 之前的研究集中在刺激子重组和排放上,不太重视它们的运输特性.
研究的目的:
- 在应用电场下的半导体量子洞中研究带电和中性激子的传输.
- 为了确定负电荷激子 (X-) 的移动性,并将其与中性激子进行比较.
- 通过刺激漂移探索通过光电子设备操纵光辐射的潜力.
主要方法:
- 制造用于半导体量子井的高电子流动性晶体管结构.
- 激光激发可以在量子井内产生激子.
- 应用源-排水电压来诱导电场并观察激电漂移.
- 使用运输实验测量刺激子的移动性.
主要成果:
- 观察到负电荷的刺激子 (X-) 在施加电压时在半导体量子井中漂移.
- 在类似的实验条件下,中性刺激子没有表现出漂移.
- 在高质量的样本中,X-的移动性被测得高达6.5 x 10^4 cm^2 V^-1 s^-1.
- 结果表明,X-在最佳条件下表现为自由粒子.
结论:
- 负电荷的刺激子 (X-) 在应用电场下的半导体量子井中表现出有针对性的运动.
- X- 的高流动性表明它存在于高质量的材料中作为自由粒子.
- 激发漂移可以用于控制光电子设备中的光辐射,为设备工程提供新的途径.
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