Variation in structure and photoluminescence in SrTiO3 film buffered by SrRuO3

► In the present paper, we find blue-light emission at room temperature is present in SrRuO3 buffered SrTiO3 film. ► We believe the phenomenon is related to internal structure. ► Multiple X-ray diffraction methods are employed to characterize the microstructure. ► We argue that the structure disorder induced by the buffer is the basis for the blue-light emission.