Photoluminescence and photocurrent characteristics of Sr1−xBaxAl2O4: Eu2+, Ni2+ phosphors

Effects of crystal structure on the photoluminescence (PL) and photocurrent (PC) characteristics of Sr1−xBaxAl2O4: Eu2+, Ni2+ phosphors were investigated as a function of Ba2+ content (0.1 ≤ x ≤ 0.5) and/or type of doping ions. PL of the specimens was blue-shifted with Ba2+ content. With increasing of Ba2+ content, the PC of the specimens was increased up to x = 0.3 and then decreased. These results could be attributed to crystallinity and structural changes from monoclinic spinel (0.1 ≤ x ≤ 0.3) to hexagonal tridymite (0.4 ≤ x ≤ 0.5). With doping of Ni2+ ion, the response time of PC was remarkably shortened while the intensity of PL was slightly decreased to the incident light, which are due to the formation of trap energy level in the band gap generate from Ni2+ ion.