Abstract:

Based on Kronig-Penney model, the changing tendency of band gap or a particular level with the volume deformation in crystalline materials has been derived. On the basis of this changing tendency, the zero-phonon CT energy is deduced to be decreased when the size of Y2O3:Eu3+ phosphor decreases in nano-scale. In addition, the rigidity decrease of lattice environment in Y2O3:Eu3+ nano-phosphor leads to the enlargement of CTS coordinate offset, an optical center would reach a higher vibration level in CT excitation. The increasing magnitude in is smaller than the decreasing magnitude of when the size of Y2O3:Eu3+ phosphor decreases in nano-scale. As a result, the CT energy is decreased, and the CT excitation spectrum shifts to lower energy.

Key words: nano-sized materials, red-shift mechanism, Kronig-Penney model, Y2O3:Eu3+ phosphor, CT excitation