Up-conversion, energy transfer and CIE analysis of Er3+/Tm3+: MCZBP glasses.

Er3+-Tm3+ ions single doped and co-doped magnesium cadmium zinc borophosphate (MCZBP) glasses were prepared with melt quenching. Their density (rho), refractive index (n), the dielectric susceptibility (chi(1)), and the nonlinear optical susceptibility (chi(3)) etc., were articulated. Upconversion photoluminescence spectrum of Er3+ doped glass has only a strong green emission around 550 nm assigned to 4S3/2 -> 4I15/2 transition, and that of Tm3+ doped glass has only a strong NIR (near infrared) emission around 820 nm corresponding to 3H4 -> 3H6 transition, while that of Er-Tm co-doped one has both of them, of which green emission intensity almost changed little, but NIR emission intensity nearly doubled. The latter can be attributed to the efficient energy transfer from Er3+ ions to Tm3+ ions, of which mechanism was explored. The CIE chromaticity coordinates, colour purity (CP), and correlated colour temperature (CCT) parameters were also computed for all glasses and reported.