TY - JOUR
T1 - Understanding the quenching nature of Mn4+ in wide band gap inorganic compounds
T2 - Design principles for Mn4+ phosphors with higher efficiency
AU - Wang, Lei
AU - Dai, Zhaoxiang
AU - Zhou, Rulong
AU - Qu, Bingyan
AU - Zeng, Xiao Cheng
N1 - Funding Information:
This work is supported by the National Natural Science Foundation of China (Grant No. 11404085, 51302059 and 51601051), the Natural Science Foundation of Anhui Province (Grant 1708085ME121), NSAF (Grant No. U1630118) and the China Scholarship Council (201606695027). X. C. Z. is supported by a State Key R&D Fund of China (2016YFA0200604) to USTC. Calculations were done in the Supercomputing Center of the University of Science and Technology of China and the Holland Supercomputing Center in the University of Nebraska-Lincoln.
Publisher Copyright:
© 2018 the Owner Societies.
PY - 2018
Y1 - 2018
N2 - Mn4+ doped phosphors, as an alternative to rare-earth element doped phosphors, have attracted immense attention owing to their ultrahigh quantum efficiency of red emission for potential applications in high rendering white LEDs (light-emitting diodes). Their performance can be largely affected by quenching phenomena such as thermal quenching, concentration quenching and the quenching induced by some intrinsic/extrinsic defects. However, the quenching mechanisms due to the defect levels and host band are still incompletely understood. In this work, we carry out a comprehensive first-principles study on the underlying quenching mechanisms due to the defect levels of Mn4+ and other extrinsic/intrinsic defects, using the prototype oxide Y3Al5O12 (YAG), fluorides K2TiF6 (KTF) and ZnTiF6·6H2O (ZTF) as examples. From the comparison of the defect levels of Mn4+ with the host bands, we find that it is the very small energy difference between the defect levels of Mn4+ and the valence bands maximum (VBM) of YAG that causes the lower luminescence thermal stability of YAG:Mn4+, which we name as the hole-type thermal quenching mechanism. For the concentration quenching, it is nearly impossible for the Mn4+-Mn4+ pairs, previously considered as the main quenching centers, to appear in phosphors. A new quenching nature has been discussed. For the impurity ionic effects, the hole-type defects can largely stabilize the Mn ions in +4 states, thereby enhancing the emission intensity. These proposed mechanisms can offer deeper insights into the luminescence behavior of Mn4+ and a better practical understanding of the high photoluminescence quantum yield red phosphors by adjusting their chemical components.
AB - Mn4+ doped phosphors, as an alternative to rare-earth element doped phosphors, have attracted immense attention owing to their ultrahigh quantum efficiency of red emission for potential applications in high rendering white LEDs (light-emitting diodes). Their performance can be largely affected by quenching phenomena such as thermal quenching, concentration quenching and the quenching induced by some intrinsic/extrinsic defects. However, the quenching mechanisms due to the defect levels and host band are still incompletely understood. In this work, we carry out a comprehensive first-principles study on the underlying quenching mechanisms due to the defect levels of Mn4+ and other extrinsic/intrinsic defects, using the prototype oxide Y3Al5O12 (YAG), fluorides K2TiF6 (KTF) and ZnTiF6·6H2O (ZTF) as examples. From the comparison of the defect levels of Mn4+ with the host bands, we find that it is the very small energy difference between the defect levels of Mn4+ and the valence bands maximum (VBM) of YAG that causes the lower luminescence thermal stability of YAG:Mn4+, which we name as the hole-type thermal quenching mechanism. For the concentration quenching, it is nearly impossible for the Mn4+-Mn4+ pairs, previously considered as the main quenching centers, to appear in phosphors. A new quenching nature has been discussed. For the impurity ionic effects, the hole-type defects can largely stabilize the Mn ions in +4 states, thereby enhancing the emission intensity. These proposed mechanisms can offer deeper insights into the luminescence behavior of Mn4+ and a better practical understanding of the high photoluminescence quantum yield red phosphors by adjusting their chemical components.
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U2 - 10.1039/c8cp02569j
DO - 10.1039/c8cp02569j
M3 - Article
C2 - 29900444
AN - SCOPUS:85049170630
SN - 1463-9076
VL - 20
SP - 16992
EP - 16999
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 25
ER -