Near-infrared quantum cutting in Bi3+/Yb3+ co-doped oxyfluoride glasses via cooperative energy transfer for solar cells

Abstract The Bi 3+ /Yb 3+ ion co-doped 55SiO 2 –20Al 2 O 3 –5Na 2 CO 3 –20CaF 2 glasses are synthesized successfully by a conventional melting-quenching method. High efficient quantum cutting involving the emission of two near-infrared photons for one ultraviolet photon absorbed is realized in the oxyfluoride glasses co-doped with Bi 3+ and Yb 3+ . An intense characteristic near-infrared emission around 977 nm of Yb 3+ : 2 F 5/2 → 2 F 7/2 transition is obtained when the 303 nm is as excitation wavelength to induce the 1 S 0 → 3 P 1 transition of Bi 3+ . The maximum quantum efficiency of our glasses is estimated to be 164.3%. The energy transfer mechanism is proposed to be a cooperative energy transfer via second-order down-conversion process. The glasses could be a potential quantum cutting converter to improve the photovoltaic energy conversion efficiency of crystalline Si solar cells via spectrum modification.