Study on the coupled multiple nanocrystal quantum-dot system

Abstract

We have studied excess electron filling rule in the coupled multiple nanocrystal quantum-dot systems, i.e. quantum chain and quantum pattern, by the unrestricted Hartree–Fock–Roothaan method. Assuming each quantum dot of quantum pattern to be confined in a three-dimensional spherical potential well of finite depth, we have studied the intradot and interdot electron Coulomb and exchange interactions. By varying the center distance d between the coupled quantum dots, the transition from the strong- to weak-coupling situation is realized. For the systems in question, our results show that, with the filling of excess electrons into the quantum pattern, the corresponding chemical potentials form quasi-band structure, which is similar to the energy-band structure of crystal material. In each chemical-potential band of quantum pattern, the number of chemical-potential curves is equal to the number of quantum dots, and the distributions of them depend strongly on the quantum-dot arrangement structure of quantum pattern.