The four-state model for electronic transitions in a hollow nanosphere. E10 and E11 are occupied states, and E20 and E21 are unoccupied states. EF is the Fermi energy. Here, we consider the electronic states in the case of m = 0. The possible transition channels are indicated.
Xiao et al. Nanoscale Research Letters 2012 7:578 doi:10.1186/1556-276X-7-578