Energy conversion dynamics of novel lanthanide-doped forsterite photoactive devices

Forsterite (Mg2SiO4) is an easily dopable dielectric oxide with elevated transparency in the ultraviolet (UV), visible (Vis), and near-infrared (NIR) ranges. Despite its properties, the use of forsterite as a phosphor host has not been extensively studied. In this paper, Mg2SiO4 was used as a host for different combinations of Er3+, Eu3+, and Yb3+. The insertion of multiple dopants in the forsterite structure is presented for the first time. DC and UC photoluminescence were measured with excitation at 380, 976, and 1470 nm. Yb3+-doped forsterite showed an elevated UC emission at 480 nm (blue) due to the cooperative luminescence (CL) allowed by the host. Interestingly, the efficiency of the Er3+ UC and DC emissions involving the 4I11/2 level considerably increased in the presence of Eu3+. The Eu3+ ion serves as energy storage for Er3+ in the Mg2SiO4 crystal, presenting a behavior never reported in other hosts. Er3+/Eu3+/Yb3+ co-doped nanoparticles showed the highest DC emission among the samples under 976 nm excitation, indicating the insertion of Eu3+ as an alternative to improve Er3+/Yb3+-doped waveguide amplifiers. Moreover, the Er3+/Eu3+/Yb3+ co-doping resulted in efficient energy conversion from the NIR and UV to the Vis, the main spectral range for solar cell applications.