Effective formation of Ag nanoclusters and efficient energy transfer to Yb3+ ions in borosilicate glasses for photovoltaic application

Borosilicate glasses containing Ag nanoclusters (Ag NCs), Eu³⁺ and Yb³⁺ were prepared with the melt-quenching method, in which an efficient energy transfer from Ag NCs to Yb³⁺ can be realized. Unlike the previous reports in which Eu³⁺ act as either sensitizer or luminescence center, the role of Eu³⁺ in this system is to promote the formation of Ag NCs and thus effectively increased the number of sensitizer at low AgNO₃ doping. With optimized AgNO₃ and YbF₃ concentrations of 0.5 and 1.0 mol% respectively, 6.3 times further enhanced Yb³⁺ infrared emission can be obtained through the introduction of trace amount of EuF₃. Additionally, the origin of Ag NCs visible emission, the mechanism that is responsible for the energy transfer from Ag NCs to Yb³⁺, and the effect of YbF₃ and EuF₃ doping on the formation of Ag NCs were discussed.