Electrical Studies of Semiconductor-Nanocrystal Colloids
Electrical Studies of Semiconductor-Nanocrystal Colloids
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半导体纳米晶体胶体的电学研究
DOI：
10.1557/s0883769400031225
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发表时间：
1998
期刊：
影响因子：
5
通讯作者：
A. Alivisatos
中科院分区：
文献类型：
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作者：
A. Alivisatos
纳米半导体晶体的研究一直在快速发展。对这些材料的大部分兴趣源于这样一个事实，即它们的物理和化学性质可以根据日益完善的标度定律通过尺寸的变化进行系统地调整。本文介绍了胶体半导体纳米晶体属于II-VI族和III-V族，并概述了获得电访问这些点的策略。如果一个无机团簇超过一定的尺寸-通常在10个晶胞中-那么它将可能具有体相的键合几何特征。在这个临界尺寸以上，团簇中化学键的性质作为尺寸的函数保持不变，但是原子的总数或表面积与体积的比率平滑地变化。这导致了一个缓慢的外推的理想纳米晶体的属性朝着体积值的大小增加，根据标度律。通过改变尺寸和形状来系统地控制无机材料的性能的能力是一个重要的发展，对材料的加工和组装有许多影响。许多标度律已被研究，包括带隙的大小变化，充电能量，磁化反转，和熔化。对标度定律的研究揭示了如何制造纳米晶体的教训。本文重点介绍胶体半导体纳米晶体的性质，如何制作它们，以及获得电访问它们的方法。在金属、磁性和结构纳米材料方面也取得了进展。Bimberg、Gammon和Tarucha在本期的文章中介绍了通过其他处理技术生产的半导体点。
The study of nanometer-sized semiconductor crystals has been advancing at a rapid pace. Much of the interest in these materials stems from the fact that their physical and chemical properties can be systematically tuned by variation of the size, according to increasingly well-established scaling laws. This article describes colloidal semiconductor nanocrystals belonging to the II-VI and III-V families, and outlines strategies for obtaining electrical access to such dots. If an inorganic cluster exceeds a certain size—generally in the 10s of unit cells—then it will likely possess a bonding geometry characteristic of a bulk phase. Above this critical size, the nature of the chemical bonds in the cluster remains fixed as a function of the size, but the total number of atoms—or the surface to volume ratio—changes smoothly. This leads to a slow extrapolation of the properties for ideal nanocrystals toward bulk values with increasing size, according to the scaling laws. The ability to control systematically the properties of inorganic materials by variation of size and shape is an important development with many implications for how materials should be processed and assembled. Many scaling laws have been investigated, including the size variation of bandgap, charging energy, magnetization reversal, and melting. Study of the scaling laws reveals lessons for how to make nanocrystals. This article focuses on the properties of colloidal semiconductor nanocrystals, how to make them, and ways of gaining electrical access to them. Advances in metal, magnetic, and structural nanomaterials are also occurring. Semiconductor dots produced by other processing techniques in the articles by Bimberg, Gammon, and Tarucha in this issue.