The rate of non-radiative
decay from a particular rare-earth energy level arise from the phonon
energy spectrum of the host material and the strength of the RE
ion–lattice coupling. Local vibrational modes related to RE ions,
their complexes, or others impurities present in a-III-nitride host,
which is AlN in our case, will also play an important role.
The strong IR emission around 1552 nm makes AlN:Er