Near-infrared quantum cutting in Pr3+/Yb3+ co-doped transparent tellurate glass via two step energy transfer

A series of Pr3+/Yb3+ co-doped transparent tellurate glass samples were prepared by high-temperature melting method. The optical properties and energy transfer process from Pr3+ to Yb3+ were investigated. On excitation of Pr3+ ions with a blue visible photon at 449 nm, a near infrared emission at 1001 nm were observed in the Pr3+/Yb3+ co-doped tellurate glass, which is attributed to 2F2/5→2F2/72F2/5→2F2/7 transition of Yb3+ ions. The feeding of Yb3+ ions is shown to be two step energy transfer from Pr3+ through 1G41G4 multiplet by excitation and emission spectra. The maximum total quantum efficiency reaches 136.7% when the co-doped Yb3+ mole concentration is 5%. The efficient down-conversion near infrared emission of Pr3+/Yb3+ co-doped tellurate glass has potential application in enhancing the conversion efficiency of crystalline silicon based solar cells.

► Tellurate glass has been employed as the host owing to its low phonon energy frequency (∼700 cm−1). ► Experimental evidence of two step energy transfer from Pr3+ to Yb3+ were obtained by emission and excitation spectra. ► The maximum total quantum efficiency reaches 136.7% when the co-doped Yb3+ mole concentration is 5%.