Figure 5

The crystal field splitting and the energy level diagram for Ce3+ in (Y1−xGdx)3Al5O12 upon substitution of Y3+ by Gd3+ and its excitation and emission processes, where Δ = 10Dq indicates the crystal splitting energy acting on the 5de-doublet state (2Eg) and the 5dt-triplet state (2Tg) in tetragonal field, Δ12 indicates an additional crystal splitting energy on the 5de-doublet state to form the 5d1 and 5d2 states, the SS denotes Stokes shift.
The splitting and transition involving the 5dt states are omitted.