Blue-light emission at room temperature from Ar+-irradiated SrTiO3

Oxide-based electronic devices are expected to have fascinating properties, unlike those made from conventional semiconductors. SrTiO 3 (STO) is a key material for this new field of electronics 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 . Here we report on blue-light emission at room temperature from Ar + -irradiated, metallic STO. The irradiation introduces oxygen deficiencies to a depth of ∼20 nm from the crystal surface. These deficiencies generate conduction carriers and stabilize a hole level in a self-trapped state. We propose a model by which the doped conduction electrons and the in-gap state produce a radiative process that results in blue-light emission. The emitting region can be patterned into any size and shape with conventional microscopic fabrication techniques.