Optical spectroscopy of rare-earth doped ternary lead based halides

Spectroscopic properties of Pr3+ and Er3+ -doped KPb2Br5 crystals were investigated for possible applications in eye-safe lasers as well as Ce3+-doped KPb2Cl5 and Eu2+-doped KPb2Cl5/KPb2Br5 for potential radiation detectors. The studied materials were synthesized through careful purification of starting materials including multi-pass zone-refinement and halogenation. The growth of the purified materials was then carried out through the vertical or horizontal Bridgman technique. Under resonant excitation, infrared (IR) emissions at similar to 1.5 mu m and similar to 1.6 mu m were observed from Er: KPb2Br5 and Pr: KPb2Br5 corresponding to the 4f-4f transitions of I-4(13/2). I-4(15/2) and F-3(4),F-3(3)-> H-3(4), respectively. Emission characteristics of the similar to 1.5 mu m Er3+ and similar to 1.6 mu m Pr3+ transitions including IR to visible upconversion emission studies were also discussed. Under xenon lamp excitation, spectroscopic results showed allowed 5d-4f Ce3+ emission centered at similar to 375 nm in Ce3+-doped KPb2Cl5. Fast photoluminescence decay time of similar to 30-50 ns was attained from Ce: KPb2Cl5, while X-ray excited emission at similar to 530 nm appeared to originate from the host KPb2Cl5 crystal. In addition, a commercial Ce: YAP (yttrium aluminum perovskite, YAlO3) crystal was included in this study for comparison. Eu2+ 5d-4f emissions were not observed from Eu(2+)doped KPb2Cl5 and KPb2Br5 crystals. (C) 2017 Optical Society of America