Scanning tunneling spectroscopy of InAs nanocrystal quantum dots
Scanning tunneling spectroscopy of InAs nanocrystal quantum dots
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DOI：
10.1103/physrevb.61.16773
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发表时间：
2000-06-15
影响因子：
3.7
通讯作者：
Banin, U
中科院分区：
文献类型：
--
作者：
Millo, O;Katz, D;Banin, U
扫描隧道光谱被用来研究单个InAs纳米晶体，直径20-70埃，在一个高度不对称的双势垒隧道结配置。I-V特性反映了量子点的单电子带电和类原子能级结构的贡献。的光谱进行了模拟和描述的“正统模型”的单电子隧穿的框架内。隧道光谱中的峰显示系统的加宽与点直径的减少，从40至150毫电子伏在所研究的量子点尺寸范围。这被分配到一个减少的电子停留时间的点，由于势垒高度的降低，诱导的量子限制水平的蓝移。发现隧穿谱中的充电多重态内的峰间距的分布是高斯的，类似于对金属量子点的观察。
Scanning tunneling spectroscopy is used to investigate single InAs nanocrystals, 20-70 Angstrom in diameter, in a highly asymmetric double barrier tunnel junction configuration. The I-V characteristics reflect contributions of both single-electron charging and the atomiclike level structure of the quantum dots. The spectra are simulated and well described within the framework of the "orthodox model" for single-electron tunneling. The peaks in the tunneling spectra display a systematic broadening with the reduction of dot diameter, from 40 to 150 meV over the studied quantum dot size range. This is assigned to a decreased electron dwell time on the dot, due to reduction of the barrier height, induced by the blueshift of the quantum-confined levels. The distribution of peak spacings within charging multiplets in the tunneling spectra is found to be Gaussian, resembling observations on metallic quantum dots.