Photoluminescence and Energy Transfer Process in Bi<sup>3+</sup>/Sm<sup>3+</sup> Co-Doped Phosphate Zinc Lithium Glasses

Present paper reports on luminescence characteristics of individually doped Bi3+: PZL, Sm3+: PZL and co-doped (Bi3+/Sm3+): PZL (50P2O5-30ZnO-20LiF) glasses prepared by a melt quenching method. The results revealed that Bi3+: PZL glass exhibited a broad emission peak at 440 nm (3P1→1S0) under excitation wavelength 300 nm (1S0→3P1). Sm3+: PZL doped glass has shown a prominent orange emission at 601 nm (4G5/2→6H7/2) with an excitation wavelength 403 nm (6H5/2→4F7/2). Later on Bi3+ is added to Sm3+: PZL glass by increasing its concentrations from 0.1 - 1.5 mol%. By co-doping Bi3+ to Sm3+: PZL glass, Sm3+ emission intensity has been considerably enhanced till 1.0 mol% due to energy transfer from Bi3+ to Sm3+ and when its concentration exceeds this critical value (1.0 mol%) there has been a drastic decrease in Sm3+ emission which is explained accordingly from photoluminescence spectra, energy level diagram and lifetime measurements.