Energy transfer of Er3+-Nd3+ co-doped in tellurite glass via energy level match

Er3+/Nd3+ co-doped tellurate glass was prepared by melt quenching method. The relationship between the energy levels of two rare earth ions was studied by absorption spectra and excitation spectra. At 379/407/488 nm excitation, visible light, near-infrared (NIR) emission spectra, and fluorescence attenuation curves were measured. The NIR emission spectrum and fluorescence lifetime show that Er3+ can transfer energy to Nd3+, thus enhancing the NIR emission of Nd3+ in tellurate glass. In the co-doped sample, under excitation of 379/407/488 nm, the NIR emission of Nd3+ has a concentration quenching point related to Er3+, and the optimal co-doped concentration is 1mol% ErF3. At 365/451 nm excitation, NIR emission was not enhanced and no energy transfer occurred. In contrast to the energy transfer between conventional Er3+-Nd3+ co-doped glasses, this paper investigates the effect of matching the higher Er3+ energy levels with adjacent Nd3+ levels on the energy transfer. The energy transfer process of Er3+-Nd3+ co-doped glasses is studied in the energy level diagram. At 379/407/488 nm excitation, the NIR emission spectrum and fluorescence lifetime show that Er3+ can transfer energy to Nd3+, thus enhancing the NIR emission of Nd3+ in tellurate glass. At 365/451 nm excitation, NIR emission was not enhanced and no energy transfer occurred. [Display omitted] •The energy transfer occurs between Er3+ and Nd3+ in the tellurate glass under 379/407/488 nm, but not under 365/451 nm.•The fluorescence lifetime of Er3+:4I13/2 reduced when Nd3+ was added to Er3+ doped glass, which verified the ET phenomenon.•The energy transfer may occur more easily if the band gap between Er3+/Nd3+ energy levels is −0.053 ev ≤ ΔE ≤ 0.102 ev.