Controlled synthesis and luminescent properties of Eu2+(Eu3+), Dy3+-doped Sr3Al2O6 phosphors by hydrothermal treatment and postannealing approach

In this work, Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors have been prepared by hydrothermal treatment and subsequently postannealing approach, using Sr(NO3)2, Al(NO3)3·9H2O, and CO(NH2)2 as starting materials. The as-obtained phosphors were characterized by means of XRPD, FESEM, and PL techniques. In addition, many reaction parameters were studied in detail, including the initial mole ratios, hydrothermal reaction temperature, calcination temperature and calcination atmosphere. Remarkably, two scientific merits exist herein: Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors can be selectively obtained in a reducing atmosphere (H2/Ar, 20%+80%) and in air, respectively; adding certain amount of sodium citrate can alter the shape and size of Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors in essence. Besides, the luminescent properties of Sr3Al2O6: Eu2+ (Eu3+), Dy3+ phosphors were studied by excitation spectra, emission spectra and decay curves.