Enhanced quantum efficiency and thermal stability in tunable yellow-emitting SrxCa1-xAlSiN3:Ce3+ phosphor.

Ce3+ doped CaAlSiN 3 is a promising broadband orange phosphor that can be applied in white light-emitting diodes (wLEDs) solid state lighting for general illumination. However, its emission color and quantum efficiency are not good enough to achieve high color rendering properties and luminous efficacy of wLEDs. In this work, we proposed to realize the spectral tuning and property enhancement of CaAlSiN 3 :Ce3+ by bandgap engineering via the cationic substitution of Ca by Sr. The relationship between photoluminescence and local coordination structure as well as electronic structure were revealed. The substitution led to a blue-shift in emission maximum by 13 nm (from 595 to 582 nm) and a highest external quantum efficiency of 55% (enhanced by 10%). This broadband yellow phosphor enabled to produce wLEDs with a color rendering index of 83.3, luminous efficacy of 114.6 l m/W and a color temperature of 4604 K. With the substitution of Ca by Sr in broadband yellow phosphor CaAlSiN 3 :Ce3+, a blue-shift in the emission maximum (from 595 to 582 nm) was attained, while the quantum efficiency and thermal stability of the phosphor containing 40% Sr were increased by 10 and 7.2% due to the decreased crystal field splitting and increased bandgap of the host. Image 1 • The bandgap engineering was adopted to realize the spectral tuning of CaAlSiN 3 :Ce3+ via the substitution of Ca by Sr. • The relationship between local structure and luminescence properties in Sr x Ca 1-x AlSiN 3 :Ce3+ was comprehensively discussed. • With the substitution, a blue-shift in the emission maximum (from 595 to 582 nm) was attained. • The quantum efficiency and thermal stability of the sample containing 40% Sr were raised by 10 and 7.2%, respectively. • This broadband yellow phosphor enabled to produce wLEDs with a color rendering index of 83.3. [ABSTRACT FROM AUTHOR]