Currently, upconversion nanocrystals and long-lasting phosphorescent particles have attracted extensive research interests for their possible applications as bio-imaging probes. However, there are few reports concerning the achievement of both upconversion luminescence of lanthanide ions and long-lasting phosphorescence of transition metal ions in a sole host so far. Herein, we demonstrate a novel calcium gallium germanium garnet (Ca3Ga2Ge3O12) host where lanthanide ions such as Tm3+/Yb3+ and transition metal ions such as Cr3+ can be easily incorporated through substituting the Ca2+ and Ga3+ respectively. This Cr/Yb/Tm: Ca3Ga2Ge3O12 phosphor exhibits both broadband near-infrared long-lasting phosphorescence of Cr3+ with an afterglow time of more than 7000s and near-infrared-to-near-infrared upconversion luminescence of Tm3+. Impressively, it is evidenced that the addition of Yb3+/Tm3+ into Cr: Ca3Ga2Ge3O12 not only results in Tm3+ upconversion luminescence but also greatly increases Cr3+ afterglow time. Based on excitation/emission, three-dimensional thermoluminescence and time-resolved luminescence spectra, the related long-lasting phosphorescence and upconversion luminescent mechanisms are systematically discussed as well.

Inorganic Chemistry全文链接：http://pubs.acs.org/doi/abs/10.1021/ic501238u?journalCode=inocaj&quickLinkVolume=53&quickLinkPage=8638&selectedTab=citation&volume=53