An efficient blue-violet phosphor: an advanced material designed for high-quality full-spectrum lighting

A highly efficient phosphor with exceptional luminescence properties is crucial for achieving high-quality solid-state white-light illumination. Here, this paper presents a groundbreaking discovery, an innovative blue-violet emitting Ba1.31Sr3.69(BO3)3Cl:Ce3+ (BSBCl:Ce3+) phosphor designed with remarkable thermal stability and quantum efficiency for full spectrum white light-emitting diodes (WLEDs). By employing a high-temperature solid-phase method, we synthesized various BSBCl:xCe3+ phosphors with different Ce3+ doping concentrations. Remarkably, BSBCl:0.03Ce3+ displays a broad excitation band from 250 nm to 400 nm, rendering it compatible with commercial near-ultraviolet (UV) LED chips. Under 330 nm excitation, this phosphor emits blue light with an astonishing 88.2% internal quantum efficiency (IQE) and an impressive 60.9% external quantum efficiency (EQE). Notably, when employed in the temperature range of 298-473 K, the synthesized BSBCl:0.03Ce3+ phosphor exhibits exceptional color stability and thermal stability (I423 K/I298 K = 83%). Utilizing BSBCl:0.03Ce3+ as the blue-violet emitting component in the fabrication of WLED devices has demonstrated significant advancements in the color rendering index. These findings underscore the potential of BSBCl:Ce3+ phosphors for a wide range of applications in health-oriented indoor illumination.

Luminescence Properties and Energy Transfer in SrLa2Sc2O7 Co-Doped with Bi3+/M (M = Eu3+, Mn4+, or Yb3+)

Series of Eu³⁺/Mn⁴⁺/Yb³⁺-doped SrLa₂Sc₂O₇:Bi³⁺ (SLSO: Bi³⁺) were synthesized by a high-temperature solid-state method, and the energy transfer of Bi³⁺→Eu³⁺/Mn⁴⁺/Yb³⁺ was observed. Under ultraviolet radiation, a 550 nm emission peak was observed, which is attributed to Bi³⁺ occupying the Sr²⁺/La³⁺ sites. Additionally, the other peaks were found to be 615, 707, and 980 nm, which are assigned to the Re³⁺ (Eu³⁺ and Yb³⁺) and Mn⁴⁺ occupying two different cationic sites. An obvious energy transfer (ET) from Bi³⁺ to Eu³⁺/Mn⁴⁺/Yb³⁺ was observed, and the tunable color, emitting from yellow to red, was obtained; the ET efficiency was about 86.2%, 78.6%, and 27.5% in SLSO, respectively. We found that the large overlap area between the emission spectrum of the sensitizer and the excitation spectrum of the activator could produce efficient energy transfer, which provided the idea for designing experiments in the future for some highly efficient energy transfer processes.

A novel red-emitting phosphor with an unusual concentration quenching effect for near-UV-based WLEDs

An unusual concentration quenching effect is caused by the anisotropic distribution of quenching centers in GdGaTi2O7:Eu3+.