Energy transfer in Er-doped SiO2 sensitized with Si nanocrystals

摘要: We present a high-resolution photoluminescence study of Er-doped ${\text{SiO}}_{2}$ sensitized with Si nanocrystals (Si NCs). Emission bands originating from recombination excitons confined in NCs, internal transitions within the $4f$-electron core ${\text{Er}}^{3+}$ ions, and band centered at $\ensuremath{\lambda}\ensuremath{\approx}1200\text{ }\text{nm}$ have been identified. Their kinetics were investigated detail. Based on these measurements, we comprehensive model for energy-transfer mechanisms responsible light generation this system. A unique picture energy flow between two subsystems was developed, yielding truly microscopic information sensitization effect its limitations. In particular, show that most ions available system are participating exchange. The long-standing problem apparent loss optical activity majority Er dopants upon NCs is clarified assigned to appearance very efficient exchange mechanism ions. Application potential ${\text{SiO}}_{2}:\text{Er}$, by discussed view newly acquired insight.