MgAl2O4 both as short and long persistent phosphor material: Role of antisite defect centers in determining the decay kinetics.

Abstract The present work describes the role of antisite defects centers in determining the phosphor characteristics of MgAl 2 O 4 , arising due to inversion nature of the spinel compound. The diverse decay characteristics impart this material both as long persistent bluish phosphor as well as short persistent red phosphors material depending upon the annealing temperature. TL study confirmed the fact that there are several defect centers which acts as electron and hole trap centers inside the band gap. FTIR and DRS study confirmed the presence of antisite defects centers viz. Al Mg + or Mg Al −, which act as an electron and hole trap centers and thereby delaying the electron-hole recombination process. Lower inversion nature of this spinel compound at higher annealing temperature results in decay in those defects concentration, as reflected in lifetime values. Graphical abstract MgAl 2 O 4 can be used both as long persistent blue emitting and as well as short persistent red emitting phosphor material depending on the annealing temperature during synthesis. Antisite defect centers such as [Al3+ Zn ] + and [Zn2+ Al ]- act as electron and hole trap centers as confirmed by TL, FTIR and DRS study are responsible for the lifetime behavior. Image 1 Highlights • The paper describes defect induced emission in MgAl 2 O 4 phosphor and role of antisite defects centers in determining the phosphor characteristics. • Upon thermal annealing the lifetime values for some color components reduced from several milliseconds to microseconds, which renders the material both as long persistent or short persistent phosphor. • TL study showed that there are several defect related trap centers present inside the band gap. • The inversion nature of the spinel compound leads to various antisite defects centers such as Al Mg + or Mg Al −, which act as a electron and hole trap centers and are mainly responsible for the diverse behaviors. [ABSTRACT FROM AUTHOR]