Enhancing thermal stability and photoluminescence of red-emitting Sr2Si5N8:Eu phosphors via boron doping

Enhanced Thermal Stability of Red‐Emitting Sr2Si5N8:Eu2+ Phosphors from Triggered Applicable Trap Level via Rare Earth Ions Co‐Doping

“…In the lattice of this system, the activator Eu 2+ replaces the site of Sr 2+ , so the chemical environment state of Sr can reflect the state of Eu. [ 20 ] For this reason, the high‐resolution XPS of Sr for these three samples was measured and analyzed, as shown in Figure 7b–d. The Sr 3d high‐resolution XPS of this system can be deconvoluted into two peaks, located at 133.4 and 135.1 eV, respectively.…”

“…When the co‐doping amount of Dy 3+ is 0.05, the ratio of Sr─N/Sr─O significantly decreases, indicating an increase in the amount of O around Sr. In this Sr environment, when Eu 2+ replaces the Sr 2+ site, it is more likely to be oxidized to form Eu 3+ , [ 20 ] becoming a quenching center of luminescence. This result is also consistent with the poor thermal stability of samples with a co‐doping amount of 0.05.…”

“…[17] Therefore, another completely different method is to adjust the overall lattice property and local coordination environment of the activator through chemical unit substitution, so as to improve the intrinsic luminescent thermal stability of the phosphor itself. Such methods include the introduction of carbon and oxygen into Sr 2 Si 5 N 8 :Eu 2+ by Tian et al [18] and Grieco et al, [19] and the introduction of boron into Sr 2 Si 5 N 8 :Eu 2+ by Shen et al, [20] all of which can improve the thermal stability of luminescence but to a limited and small extent. Liu et al substituted (Ca 0.55 Ba 0.45 ) 2+ for Sr 2+ [16] and our previously reported co-substitution of Ba 2+ -(AlO) + for Sr 2+ -(SiN) + .…”

“…Such methods include the introduction of carbon and oxygen into Sr 2 Si 5 N 8 :Eu 2+ by Tian et al. [ 18 ] and Grieco et al., [ 19 ] and the introduction of boron into Sr 2 Si 5 N 8 :Eu 2+ by Shen et al., [ 20 ] all of which can improve the thermal stability of luminescence but to a limited and small extent. Liu et al.…”

Progress of M2Si5N8:Eu series in industrial LED phosphors

“…Yuan et al tried to introduce B 3+ in Sr 2 Si 5 N 8 :Eu 59 for the improvement of the thermal degradation of Sr 2 Si 5 N 8 :Eu. 60,61 The oxidation process of Eu 2+ in Sr 2 Si 5 N 8 :Eu can be expressed by the following equation: 62 2Eu 2+ + 1/2O 2 (g) + V N → 2Eu 3+ + O N 2− where V N is a nitrogen vacancy.…”