Structural-suppressing concentration quenching in dysprosium single-phase white emission and their application in optical thermometric and white light-emitting devices

Abstract

Single Dy3+ doped material is indispensable to establish single-phase white emission. However, concentration quenching (CQ) and poor stability limit its wider application. Herein, Dy3+-doped Ca3LuAl3B4O15 (CLAB:Dy3+) is reported to be an advanced dual-emitting micro phosphor with promising optical properties making it a promising applicant with potential applications in thermometric and n-WLEDs. The host has a highly disordered crystal structure, suppressing the CQ phenomena of Dy3+, and attains a high doping level. Using the Kubelka–Munk equation, the optical bandgap Calculated for the matrix is 4.66 eV, which is ideal for n-WLEDs. Under 350 nm UV light, the prepared CLAB:Dy3+ displayed emissions at 476 nm and 569 nm with a CIE diagram of (0.382, 0.402) and IQE up to 18.3%. The Blass and Dexter model analyzed the energy migration (EM) mechanism. The dual emissions in CLAB:Dy3+ have distinct thermal reactions caused by thermal quenching. The temperature sensing properties of CLAB:0.08Dy3+ ranging from 300 to 500 K was examined and showed a superb Boltzmann distribution behavior between 455 nm and 476 nm fluorescence intensity ratio (FIR) and the optimum relative sensitivity SR value of 1.46% K−1. Employing the CLAB:Dy3+, a fabricated phosphor-converted white light-emitting diode (pc-WLED) emitted white light with CIE (0.36, 0.39), a color rendering index (CRI = 67.5), and a low color coordinate temperature (CCT = 4624 K). These findings suggest that this incredibly efficient single-phase white-emitting material has great potential for optical thermometric and pc-WLEDs.