Search

Mn4+-activated oxide red phosphors are always a hot topic in the luminescent material field to solve the lack of red light components in white-light-emitting diodes (WLEDs). Herein, a series of novel deep red-emitting CaAl12−mPmO19+m:0.01Mn4+,0.2Mg2+ (m = 0–0.15) phosphors were synthesized and their crystal structure, luminescence properties and thermal stability were investigated in detail. The high-valence P5+ is used to replace low-valence Al3+ in the luminescent host CaAl12O19 to improve the photoluminescence quantum yield (PLQY) of phosphors. The doping of P5+ does not change the crystal phase structure of phosphors, and the luminescence intensity and PLQY are significantly enhanced. The analysis of the photocurrent and fluorescence lifetime shows that an electron trap with a quantum-confinement structure is formed in the phosphor host, which plays a key role in buffering photogenerated electrons. Therefore, the PLQY of the P5+-doped CaAl11.90P0.1O19.10:0.01Mn4+,0.2Mg2+ phosphor increased from 9.8% (P5+-undoped) to 70.2%, and the mechanism of PLQY enhancement is proposed based on the analysis of the crystal structure. Furthermore, the phosphor has superior thermal stability and color purity (96.8%). Overall, this work provides new insights and ideas on quantum confinement effects for improving the quantum yield of Mn4+-activated luminescent materials. [ABSTRACT FROM AUTHOR]

Mn 4+ -activated oxide red phosphors are always a hot topic in the luminescent material field to solve the lack of red light components in white-light-emitting diodes (WLEDs). Herein, a series of novel deep red-emitting CaAl 12- m P m O 19+ m :0.01Mn 4+ ,0.2Mg 2+ ( m = 0-0.15) phosphors were synthesized and their crystal structure, luminescence properties and thermal stability were investigated in detail. The high-valence P 5+ is used to replace low-valence Al 3+ in the luminescent host CaAl 12 O 19 to improve the photoluminescence quantum yield (PLQY) of phosphors. The doping of P 5+ does not change the crystal phase structure of phosphors, and the luminescence intensity and PLQY are significantly enhanced. The analysis of the photocurrent and fluorescence lifetime shows that an electron trap with a quantum-confinement structure is formed in the phosphor host, which plays a key role in buffering photogenerated electrons. Therefore, the PLQY of the P 5+ -doped CaAl 11.90 P 0.1 O 19.10 :0.01Mn 4+ ,0.2Mg 2+ phosphor increased from 9.8% (P 5+ -undoped) to 70.2%, and the mechanism of PLQY enhancement is proposed based on the analysis of the crystal structure. Furthermore, the phosphor has superior thermal stability and color purity (96.8%). Overall, this work provides new insights and ideas on quantum confinement effects for improving the quantum yield of Mn 4+ -activated luminescent materials.