ABSTRACT
Semiconductor nanostructures, which have one dimension of the order of 10−9 m, have attracted huge interest from the scienti c community due to the unique quantum con nement e ects that become important on this scale, and the resulting potential for size-tunable nanodevices (Cui and Lieber 2001; Duan et al. 2003). Such nanostructures include (1) quantum wells, e.g., a heterostructure or superlattice, which are two-dimensional structures and con ned in one dimension; (2) quantum wires, a one-dimensional structure con ned in two dimensions; and (3) quantum dots, a zero-dimensional structure con ned in three dimensions. ese systems are illustrated in Figure 18.1, as well as the three-dimensional bulk system. e terminology of “quantum” indicates that the electronic properties become quantized as the size of a dimension(s) of the structure diminishes, that is, they change from being continuous to discrete values, as depicted in the electronic density of states shown in Figure 18.1.
