Yu Heng, Li Jingbo, Loomis Richard A, Wang Lin-Wang, Buhro William E
Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, USA.
Nat Mater. 2003 Aug;2(8):517-20. doi: 10.1038/nmat942.
The size dependence of the bandgap is the most identifiable aspect of quantum confinement in semiconductors; the bandgap increases as the nanostructure size decreases. The bandgaps in one-dimensional (1D)-confined wells, 2D-confined wires, and 3D-confined dots should evolve differently with size as a result of the differing dimensionality of confinement. However, no systematic experimental comparisons of analogous 1D, 2D or 3D confinement systems have been made. Here we report growth of indium phosphide (InP) quantum wires having diameters in the strong-confinement regime, and a comparison of their bandgaps with those previously reported for InP quantum dots. We provide theoretical evidence to establish that the quantum confinement observed in the InP wires is weakened to the expected extent, relative to that in InP dots, by the loss of one confinement dimension. Quantum wires sometimes behave as strings of quantum dots, and we propose an analysis to generally distinguish quantum-wire from quantum-dot behaviour.
带隙的尺寸依赖性是半导体中量子限制最显著的方面；随着纳米结构尺寸减小，带隙增大。由于限制维度不同，一维（1D）限制阱、二维（2D）限制线和三维（3D）限制点中的带隙随尺寸的变化应该不同。然而，尚未对类似的1D、2D或3D限制系统进行系统的实验比较。在此，我们报告了处于强限制区域、具有特定直径的磷化铟（InP）量子线的生长情况，并将其带隙与先前报道的InP量子点的带隙进行了比较。我们提供了理论证据来证明，相对于InP量子点，InP量子线中观察到的量子限制因失去一个限制维度而减弱到预期程度。量子线有时表现为一串量子点，我们提出了一种分析方法来普遍区分量子线和量子点的行为。
