A novel blue emitting phosphor LaScO3:Bi3+ for white LEDs: high quantum efficiency, high color purity and excellent thermal stability

Series of blue phosphors La1-xBixScO3 (x = 0-0.6) (LSO) were synthesized by the high temperature solid state method. Under the 365 nm near ultraviolet (NUV) irradiation, when the value of x is increased, the phosphor can emit blue from deep to shallow. The LSO phosphor presents an internal quantum efficiency of up to 98%, high color purity of 92.26% as well as excellent thermal stability. When x >= 0.2, Bi3+-doped phosphors have diverse FWHM ranging from 153 nm to 43 nm. Especially, when x = 0.5, the material shows an abnormal thermal quenching, and emission intensity at 573K can reach 128.3% of that at room temperature. The white light emitting diode (LED) was fabricated by combining the NUV LED chip (370 nm) with a mixture of LSO:0.007Bi(3+) along with green Y-3(Al,Ga)(5)O-12:Ce3+ and red CaSiAlN3: Eu2+ phosphors, which show a high color rendering index R-a = 90.2, a low correlated color temperature CCT = 3999 K. The results demonstrate that LSO phosphor has potential application in the field of white LEDs. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

A series of blue phosphors La1-xBixScO3 were synthesized, and their emission color can be tuned from deep blue to light blue by adjusting the doping concentration. The synthesized phosphors exhibited high quantum efficiency, high color purity, and excellent thermal stability. When combined with other phosphors, the white LEDs achieved high color rendering index and low correlated color temperature.