Room-temperature photoluminescence from Tb3+ ions in SiO2 and a-SiC:H thin films deposited by magnetron co-sputtering

The laser excited photoluminescence (PL) of SiO2 and a-SiC:H thin films doped with Tb deposited by co-sputtering has been studied. In the case of SiO2:Tb the PL is due to 4f–4f transitions of Tb3+ ions starting from the 5D4 level which is resonantly excited by the 488 nm Ar+ laser line. The PL in this case has no temperature quenching from 18 K up to room temperature. The inhomogeneous broadening of the PL bands predominates over the homogeneous one. In the case of a-SiC:H:Tb a broad band covering the whole visible spectrum is observed. It is tentatively assigned to a recombination centre created by the Tb impurity.