Tuning the defect state color centers in CaO powder and wafer by using hard X-ray nanoprobe

• The capabilities of changing color centers emission by using hard X-ray irradiation have been exhibited clearly. • The creation and suppression of F color centers in CaO powder and wafers have been demonstrated via XEOL. • The dynamics of luminescence of CaO powder and wafer has been studied by TR-XEOL. In this study, we utilized a hard X-ray nanoprobe to tune the defect state color centers in CaO powder and wafers. Through time-dependent X-ray excited optical luminescence (XEOL), we clearly demonstrated the creation and suppression of F color centers in CaO powder and wafers, respectively. We observed that the emission intensity of the F color in CaO powder increases with X-ray irradiation, while in CaO wafers the emission intensity decreases. This difference is attributed to the creation of new color centers and conversion of F + to F color center in powder whereas X-ray radiation induced annealing effect passivation in wafer. Furthermore, TR-XEOL decay lifetime show that the decay lifetime in powder is shorter than in comparison to the wafer.