Photoluminescence of Tb-doped SiNx films with different Si concentrations

Tb3+-doped SiNx films (SiNx:Tb3+) were prepared by plasma-enhanced chemical vapor deposition (PECVD) and ion-implantation. And the effects of the SiNx substrates with different Si concentrations on the light emission of Tb3+ were investigated. Experimental results show that two groups of photoluminescence (PL) peaks of Tb3+ ions were observed in different SiNx:Tb3+ films. And the PL intensity increased with annealing temperature. The defect states of N and Si dangling bonds of the SiNx substrate had little effect on the light emission of Tb3+ after the high-temperature annealing. For the annealed Si-rich SiNx (SRN) film, Si nanoclusters precipitated from the host matrix. The increased oxygen concentration and the optical absorption due to the band tail states and Si nanoclusters of the annealed SRN film decreased the light emission of Tb3+ ions.