Radiative transition properties of Yb3+ in Er3+/Yb3+ co-doped NaYF4 phosphor

Abstract

Usually, it is difficult to quantitatively express the optical transition properties of Yb 3+ in powdered samples owing to the difficulty in measuring the absolute absorption spectra. In this work, we developed an approach for confirming the absorption and emission cross section spectra and the radiative transition rates for the absorption and emission transitions between 2 F 7/2 and 2 F 5/2 states of Yb 3+ . The proposed approach was examined for Yb 3+ in Er 3+ /Yb 3+ co-doped NaYF 4 powders. The absorption cross section for 2 F 7/2 → 2 F 5/2 transition and emission cross section for 2 F 5/2 → 2 F 7/2 transition of Yb 3+ in NaYF 4 :Er 3+ /Yb 3+ were confirmed. Meanwhile, the transition rates for the absorption and emission transitions were also calculated. A route for calculating the radiative transition rate, absorption and emission cross sections of Yb 3+ in powdered samples is proposed. Furthermore, the radiative transition properties of Yb 3+ in NaYF 4 :Er 3+ /Yb 3+ phosphor derived from an auto-combustion-assisted fluoridation was studied via our proposed route. • NaYF 4 : Er 3+ and NaYF 4 : Er 3+ /Yb 3+ phosphors were prepared via an auto-combustion assisted solid-state reaction. • A new calculation method of radiation transition rates of Yb 3+ was proposed and used for Er 3+ /Yb 3+ co-doped NaYF 4 powders. • The absorption cross section spectra of Er 3+ /Yb 3+ co-doped NaYF 4 and Er 3+ doped NaYF 4 powders were confirmed. • The absorption and emission cross sections of Yb 3+ in NaYF 4 were derived. • The transition rates of Yb 3+ for the absorption ( 2 F 7/2 → 2 F 5/2 ) and emission ( 2 F 5/2 → 2 F 7/2 ) transitions were calculated.