Enhanced persistent luminescence and photocatalytic properties of Ga_2O_3:Cr^3+ by In^3+ doping

Abstract

Ga2O3:Cr3+, In3+ phosphors, synthesized via a high temperature solid state reaction, exhibit photocatalytic activity and persistent luminescence. With substituting In3+ for Ga3+ in Ga2O3:Cr3+, the duration of near-infrared (NIR) persistent luminescence was prolonged obviously at room temperature under 254 nm ultraviolet (UV) excitation and the photocatalytic activity was highly improved. The emission and excitation spectra indicated that In3+ doping has no obvious effect on peak positions of Ga2O3:Cr3+. The thermoluminescence (TL) curves showed that a new suitable trap was introduced into Ga2O3:Cr3+ by In3+ doping. It was considered that photocatalytic activity and persistent luminescence properties are highly associated. What’s more, the new trap plays an important role for capturing photo-generated electrons or holes, which is highly responsible for the high separation of photo-generated electron-hole pairs and could improve the persistent luminescence and photocatalytic properties of Ga2O3:Cr3+ effectively.