Near infrared quantum cutting in Yb3+-doped NaY(WO4)2 phosphor with a high quenching concentration

The near infrared quantum cutting phenomenon has been demonstrated in Yb3+-doped NaY(WO4)2 phosphor. The phosphor shows intense absorptions in the range of 250-330 nm, and intense near infrared emission is obtained via cooperative energy transfer from the host to Yb3+, which involves the emission of two near infrared photons around 1000 nm from an absorbed ultraviolet photon. Decay curves of the host emission around 480 nm have been measured, and the calculated energy transfer efficiency turns out to be as high as 81.6% at 40 mol% Yb3+ doping. Besides, infrared emission intensities increase with increasing Yb3+ concentration until the doping gets larger than 40 mol%. The excellent luminescence properties of the Yb3+-doped NaY(WO4)2 phosphor demonstrate its potential application as a better quantum cutting layer to enhance the energy efficiency of solar cells.