Charge compensation-assisted photoluminescence in an efficient K2SrP4O12:Sm3+ phosphor

Abstract

Benefiting from the visible light emission behavior of the Sm3+ activator, Sm3+-incorporated inorganic phosphors have received considerable interest in solid-state lighting areas. Nevertheless, so far, highly efficient and heat-resistant optical materials activated with Sm3+ are scarce. In this work, a series of new orange-red-emitting phosphors K2SrP4O12 (KSPO):Sm3+,A+ (A+ = Li, Na, and K) were prepared by charge compensation strategy. Under 405 nm excitation, the phosphors exhibit strong orange-red emission. The incorporation of alkali metals A+ effectively compensates for the vacancy defects caused by the non-equivalent substitution of Sm3+ for Sr2+, improving the luminescent performance. In particular, the Na+-compensated phosphor exhibits a luminescence intensity 1.92 times greater than that of the uncompensated sample due to the fact that Na+ and Sr2+ have close ionic radii. It has demonstrated excellent internal quantum efficiency (37.1 %), high color purity (98.5 %), and high thermostability (94 %@423 K), significantly surpassing the majority of reported Sm3+-doped phosphors. In addition, a representative KSPO:0.03Sm3+,0.03Na+ phosphor is used to prepare W-LEDs, showing potential for solid-state lighting.

Keywords

• Sm3+
• Phosphate
• Phosphor
• Charge compensation
• Photoluminescence