Excitation mechanism of Tb3+ in a-Si3N4:H under sub-gap excitation

We studied a sample of Tb-doped a-Si3N4:H prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD). The sample has an optical gap E04 = 4.7 ± 0.3 eV and refractive index n (at 632 nm) = 1.81 ± 0.01. Room temperature photoluminescence was measured under sub-gap excitation. Both characteristic a-Si3N4:H and Tb3+ photoluminescence peaks were detected in the sample as deposited. Annealing at 300 °C maximizes …