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-VXO] and Mg''Sn, correspond to the components at 85 ?C, 146 ?C and 213 ?C of the thermoluminescence curve.