Single Molecule Quantum-Confined Stark Effect Measurements of Semiconductor Nanoparticles at Room Temperature
Single Molecule Quantum-Confined Stark Effect Measurements of Semiconductor Nanoparticles at Room Temperature
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DOI：
10.1021/nn303719m
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发表时间：
2012-11-01
期刊：
影响因子：
17.1
通讯作者：
Weiss, Shimon
中科院分区：
文献类型：
--
作者：
Park, KyoungWon;Deutsch, Zvicka;Weiss, Shimon
在室温下，我们在单分子水平上测量了几种类型的荧光胶体半导体量子点和纳米棒的量子受限斯塔克效应(QCSE)。这些测量证明了这些纳米颗粒在纳米尺度上用于局部电场(电压)传感的可能用途。在这里，我们证明了一个(或多个)具有II型能带排列的异质结构界面(S)上的电荷分离(以及相关的感生偶极子)对于增强的QCSE是至关重要的。为了进一步了解实验结果，我们数值求解了自洽场近似下的薛定谔方程和泊松方程，包括介电不均匀。计算和实验都表明，初始电荷分离的程度(以及相关的激子结合能)决定了这些结构中QCSE的大小。
We measured the quantum-confined Stark effect (QCSE) of several types of fluorescent colloidal semiconductor quantum dots and nanorods at the single molecule level at room temperature. These measurements demonstrate the possible utility of these nanoparticles for local electric field (voltage) sensing on the nanoscale. Here we show that charge separation across one (or more) heterostructure interface(s) with type-II band alignment (and the associated induced dipole) is crucial for an enhanced QCSE. To further gain insight into the experimental results, we numerically solved the Schrodinger and Poisson equations under self-consistent field approximation, including dielectric inhomogeneities. Both calculations and experiments suggest that the degree of initial charge separation (and the associated exciton binding energy) determines the magnitude of the QCSE in these structures.