Spectroscopic properties of rare-earth complexes of tetraphenyl porphyrin introduced into a silicate sol-gel matrix

This paper presents the results of studies of a silicate sol-gel matrix doped with Er³⁺ and Nd³⁺-tetraphenyl porphyrin complexes. Based on spectroscopic measurements, it is established that the tetraphenyl porphyrin molecule can serve as a distinctive protective screen for the erbium ions. The half-width of the luminescence line of the erbium ion for the ⁴S_3/2 → ⁴I_15/2 transition was a factor of 5-6 narrower in the new silicate sol-gel material than the corresponding values in erbium glasses or ceramic. The analogous results for neodymium complexes are expressed more weakly, and this can mean that a specific molecular screen needs to be chosen for each rare-earth ion individually.