能带理论表明,在高温或宏观尺寸情况下,金属费米能级附近的电子能级往往是连续的,即大粒子或宏观物体的能级间距几乎为零。但当粒子尺寸下降到某一值(如达到纳米级)时,金属费米能级附近的电子能级由准连续变为离散能级的现象和能隙变宽的现象均称为量子尺寸效应。量子尺寸效应 Band theory shows that at high temperatures or macroscopic dimensions, the electron levels near the Fermi level in the metal tend to be continuous, ie, the energy level spacing of large particles or macroscopic objects is almost zero. However, when the particle size drops to a certain value (for example, reaching the nanoscale), the phenomenon that the electron energy level near the Fermi level of the metal changes from a quasi-continuous to a discrete energy level and the broadening of the energy gap are both referred to as the quantum size effect . Quantum size effect