Photoluminescence and persistent luminescence properties of non-doped and Ti⁴⁺-doped Mg₂SnO₄ phosphors

Mg₂SnO₄ exhibits green photoluminescence and persistent luminescence, which originate from oxygen vacancies. When Ti⁴⁺ions were doped, an interesting Mg₂SnO₄:Ti⁴⁺ phosphor with bluish white photoluminescence under ultraviolet irradiation and with green persistent luminescence was first obtained. Our investigation reveals that two emission centres exist in Mg₂SnO₄:Ti⁴⁺. The centres responsible for the green emission are considered to be the F centres (oxygen vacancies) and the blue centres are the TiO₆ complex. Trap clusters in the band gap with different depths, such as Sn_Mg^‥—O_i^″, Sn_Mg^‥—V_O^·, Sn_Mg^‥—V_O^× and Mg_Sn^″, correspond to the components at 85 ℃, 146 ℃ and 213 ℃ of the thermoluminescence curve.