Strong light emission from stress-activated perovskite-related oxides

摘要

We report mechanoluminescence (ML) in Sm~(3+)-doped Sr_3Sn_2O_7 phosphors with perovskite-related structure. The ML from Sr_3Sn_2O_7:Sm~(3+), emitted strong reddish-orange light upon compression, is clearly observable by naked eyes. Based on the comparison between ML spectrum and photoluminescence spectrum, the ML emission was identified to be due to electron transition from an excited state ~4G_(5/2) to the ground state ~6H_J (J = 5/2, 7/2, 9/2) in Sm~(3+) ions. Although the ML emission was gradually decayed as compressive load was applied repeatedly, it recovered completely upon irradiation with UV light (254 nm). This behavior indicating that ML of Sr_3Sn_2O_7:Sm~(3+) is intimately related to the charge traps. The charge transfer state (CTS) band in the PL excitation spectra was observed for Sr_3Sn_2O_7:Sm~(3+), indicating that the efficient energy transfer from the host to the Sm~(3+) ions. The formation of CTS and the charge traps may be responsible for this ML performance.