Mn2+-Yb3+ back and forth energy transfer by super-exchange interaction in bismuth silicate glass

Bismuth silicate glasses at various compositions of Mn2+ and Yb3+ were successfully synthesized by conventional melt and quenching method of 40% Bi2O3: 60% SiO2. Mn2+ presents a simultaneous green-orange emission by means of simultaneous four and six folded coordination when exciting with 350 nm and by up-conversion when exciting with 980 nm Yb3+ presents its known 976 nm emission by its 2F5/2 → 2F7/2 transition when exciting at 350 nm in 6A1(S) → 4E(D) Mn2+ energy level. This is proposed to be possible by the existence of Mn2+-Yb3+ dimers, that produce new energy levels seen in absorbance and excitation scheme labeled as 2F7/26A1(S) → 2F5/24T2(G), 2F7/26A1(S) → 2F5/24T1(G), 2F7/26A1(S) → 2F7/24T2(G) and 2F7/26A1(S) → 2F7/24T1(G) centered at 471, 521, 588 and 622 nm respectively. An energy diagram is presented to show the mechanism of this back and forth energy transfer. Absorbance, x-ray diffraction, excitation and emission spectroscopic studies are shown. •Mn2+-Yb3+ co-doped bismuth silicate glass is prepared.•There is a back and forth energy transfer between Mn2+ and Yb3+.•Mn2+ is in four and six folded coordination simultaneously.•The energy transfer is achieved by Mn2+-Yb3+ super-exchange interaction.